Regarding legal notice - india

You can issue a legal notice instructing that person to refrain from indulging in illegal activities of falsely claiming your property and trying to interfere in your possession and enjoyment of the property which you purchased by a registered sale deed.

What is the document you are expecting from him and what is the necessity to give him time to produce them.

If at all he has any claim let him approach court for relief.

Don't guide him about the action to be taken on this.

Issue legal notice through your lawyer wherein not more than one month's time should be given to the opposite party. 

In India, a legal notice typically specifies a timeframe for the recipient to respond or take action. While there's no fixed timeframe, 30 days to 60 days is a common duration specified in legal notices. However, it's possible to specify a longer timeframe, like 6 months, depending on the circumstances and the purpose of the notice. Keep in mind that the timeframe should be reasonable and fair, allowing the recipient sufficient time to respond or comply. If the timeframe is too short, the notice might be considered invalid or defective.

it is not advisable to give such time, send a notice after getting all documents if not he can always proceed after getting the notice.