The signature of the buyer not required during the year 1994, however, someone on behalf of the buyer might have signed the deed, you can contact any local document writer for this information if it is necessary you can error-free through rectification deed. 

You need to get it rectified if the previous owner is alive by execution of a rectification deed if not yes it may create problem when your wife tries to sell the property to prospective buyers

Yes if buyer sign in deed is not there meaning there by the sale is not properly executed menaing there by the defect in title to it will hamper the future sale. So a confirmation deed can be made and registered between old seller and father confirming the older trasaction. 

Yes you can resolve the same by executing a rectification deed and registering the same.

your father missing signature would create problems in case your wife tries to sell flat 

2) you can make application to registrar to issue summons to father in law to remain present before registrar office . Discretion of registrar to pass such order 

3) re registration of sale deed can be done as buyer signature is missing in sale deed 

Dear Sir,

Yours is a absolute property. No body has challenged the title of your father in law who has perfected his title by remaining and enjoyning the property for more than twelve years. Further not finding the signature on the sale deed cannot lead to cancellation of entire sale deed as there is enormous time delay and there is implication of sale by all the parties. The records maintained by the Sub Registrar Office can be called for to find out the signature of buyer there his signature and thumb impression will be there. It is presumed under law. If you still doubt then get file suit for declaration against your father and get your wife’s land declared. Never disclose that weak point at any point because it was acted upon for all these long years.

1. Sir you have to.file an declaration suit based on the  document ts you have in the civil court. Declaring ownership on the said property vide court orders.

You can approach court and file suit under 26 of specific relief act,The law provides for relief to parties in case the real intention of the party is not properly reflected in the documents executed because of a bona fide mistake of fact.

Deed of rectification is to be executed if in sale deed there is no signature of buyer 

2) if seller cannot be traced you may file a suit before a court under Section 26 of Specific Relief Act 1963. The law provides for relief to parties in case the real intention of the party is not properly reflected in the documents executed because of a bona fide mistake of fact. . The court can direct the rectification of an instrument, if it is satisfied that the deed does not express the real intention of the parties. This relief is entirely discretionary. 3) There is no specific period of limitation fixed for filing the suit for rectification. Thus the residuary Article- 113 is applicable.you ought to file suit within three years from the date of the sale deed. From the date of the sale deed itself, the time starts to run for filing the suit

1. The title of your father-in-law is defective if his signature does not appear in the sale deed. It is trite law that no one can pass a title better than his own title. He had no competence to execute the gift deed in favour of your wife as he had no title to the property in the first place.

2. The only remedy for your father-in-law is to trace the seller and ask him to execute a fresh sale deed in his favour. There is no alternative remedy.

Pursuant to the purchase of the land, your father-in-law must have gotten all the revenue documents duly transferred into his name. That completes the due process of transfer from previous owner to present owner. If the original sale deed did not have a separate column for the buyer and his signatures then it can be safely assumed that the Deed of transfer was completed successfully by the Seller affixing his signatures in all the pages of the said sale deed. If the signatures of the buyer were found in one page and not in the other pages, then such an error could have been duly corrected or rectified through a rectification deed, in this case the same is not required.

Post the sale in 1994, none of the sellers or their legal heirs or persons duly authorized by them have approached your father in law questioning the said sale in his favour. If this was to be disputed a period of 12 years is set by the Law of Limitation seeking to question the title or ownership over the site. Hence this would not be a bar for your wife to sell the property in whose ever favour she wants.

It may create the problem, please rectify the deed

File suit before the court under section 26 special relief act 1963S

Section 26 of the Special Relief Act 1963 (hereinafter referred to as ‘Act’) provides for rectification of instruments, where through fraud or a mutual mistake of the parties, an instrument in writing does not express the real intention, then the parties may apply for rectification. However, clause 4 thereof, provides that such a relief cannot be granted by the court, unless it is specifically claimed. 

Than the sale deed is incomplete and its not valid as per Indian Contract Act., 

If the  property  is transfferred in the name of buyer than as per Limitation Act you don't have rights to ask for revocation of the agreement as time limt has been passed away.