Rule 59 of the Patents Rules, 2003
Filing of reply evidence by opponent
Rule 59 lets the opponent file reply evidence within one month, strictly limited to answering matters raised in the patentee's evidence.
Official legal text
The verbatim statutory text of this provision is reproduced from the official source and checked by our legal reviewer before it is published here. Until that check is complete for this page, read the exact wording directly from the official source linked below — it is the only version that governs.
Read this as a plain-language summary. If it and the official text, or a relevant Gazette notification, say different things, the official text and the notification are what count.
What this rule requires, step by step
By the time the patentee's reply statement and evidence are on file, both sides have set out their positions. Rule 59 gives the opponent one carefully limited chance to respond. Within one month from the date the patentee's reply statement and evidence are delivered, the opponent may file further evidence, and must deliver a copy to the patentee. This closes the ordinary exchange of evidence in a post-grant opposition.
The important word is strictly. Reply evidence must be confined to matters raised in the patentee's evidence. It is not an opportunity to file the prior art that should have gone in with the written statement, or to open a new ground of opposition. If the patentee's expert says that a cited document would not have been read by a person skilled in the field, the opponent may answer that point with evidence. If the patentee produces test results, the opponent may answer with its own results on the same question. Anything wider is likely to be refused or to require leave under Rule 60.
This structure exists for a reason. Indian opposition proceedings are meant to run on a fixed timetable so that the Opposition Board and the Controller can work from a settled record. Allowing an opponent to reopen its main case at the reply stage would let it hold back its best material until the patentee had shown its hand, which is unfair and slows everything down.
Practically, the one month is tight, especially when expert evidence is involved. An opponent who expects the patentee to rely on comparative test data should line up its own expert while the reply is awaited, rather than starting after the papers arrive. Where the patentee has raised something genuinely unforeseeable and more time or wider evidence is needed, the correct step is to apply to the Controller under Rule 60 for leave, explaining why the material could not have been filed earlier, rather than to file late and hope it is accepted.
Why this rule matters
Opponents in post-grant opposition proceedings, and patentees who need to know when the record closes.
In the month after the patentee's reply statement and evidence are delivered.
A limited right of reply on the evidence, and a matching duty to stay within the boundaries of what the patentee raised.
An opponent who lets the month pass, or who files sweeping new material, may find the answer to the patentee's key point never reaches the record.
How it works in practice
Answering a test report, not reopening the case
Palakkad Spice Systems is opposing a granted patent on a low-temperature drying process. Its written statement relied on two earlier publications. In reply, the patentee files an affidavit with laboratory data claiming that the earlier process cannot hold moisture content below a stated level, so the claimed invention solves a problem the prior art could not. Palakkad's agent sees at once that this is exactly what reply evidence is for. Within the month, the company files an affidavit from a food technology professor at a Thrissur college, reporting tests run on equipment built to the earlier publication and showing the stated moisture level was in fact achieved. The affidavit deals only with the patentee's data and does not introduce new prior art, even though the company has since found a third publication. For that third document, the agent files a separate application for leave under Rule 60, explaining when and how it was located. The record stays clean and the reply evidence is admitted without argument.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- The opponent may file reply evidence within one month of delivery of the patentee's reply statement and evidence.
- A copy must be delivered to the patentee.
- Reply evidence must be strictly confined to matters raised in the patentee's evidence.
- It cannot be used to introduce prior art that belonged in the original written statement.
- New or wider material requires the Controller's leave under Rule 60.
- Reply evidence normally closes the exchange before the Opposition Board reports and the hearing is fixed.
Common mistakes and misunderstandings
- Using the reply stage to file prior art discovered late without seeking leave. It will usually be objected to and may be excluded.
- Starting to look for an expert only after the patentee's evidence arrives, when the whole window is one month.
- Repeating the original written statement in affidavit form instead of answering the specific points the patentee raised.
- Forgetting to serve a copy on the patentee, which creates avoidable disputes about what is properly on the record.
Connected provisions
Every rule traces back to a section. The linked sections are shown apart from the rule because the two are separate instruments, and because a rule that goes beyond its parent section can be challenged. Knowing the parent provision is part of reading the rule properly.
Forms, deadlines and fees
- Reply evidence must be filed within one month from the date of delivery of the patentee's reply statement and evidence.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
This site does not carry a fee table. The First Schedule to the Patents Rules is the source, the rates vary with the applicant's category and with the mode of filing, and a figure quoted second-hand goes out of date quietly. How Indian patent fees work.
Related judgments
Case summaries are published only after a qualified reviewer has checked the judgment, the citation and the way the holding is described. Nothing has cleared that review for this provision yet, so nothing is listed here. We would rather show no case note than one that misstates what a court decided. How case notes are prepared.
Questions people ask about Rule 59
What can an opponent include in reply evidence?
Only material that answers something in the patentee's evidence. Typical examples are counter test data, an expert response to the patentee's expert, or proof about a publication date the patentee has questioned. It is not a chance to file prior art you should have filed earlier or to raise a new ground of opposition. If you need to go wider, apply for the Controller's leave under Rule 60 and explain honestly why the material was not available earlier.
Can the one month for reply evidence be extended?
The Patents Rules contain a general power to extend certain periods on a request with the prescribed fee, and the Controller also has power to condone delay in defined situations. Neither should be treated as automatic. The practical approach is to apply before the period ends, set out the reason clearly, and show that the other side is not prejudiced. Assuming an extension will be granted and filing late is a poor strategy in opposition work.
What happens after reply evidence is filed?
The exchange of evidence is normally complete. The documents go to the Opposition Board, which studies them and submits its reasoned recommendation to the Controller. The Controller then fixes a hearing, giving the parties notice, and the recommendation should be made available to the parties before that hearing. After hearing both sides the Controller decides whether to maintain the patent, maintain it in amended form, or revoke it, and may also deal with costs.
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