Cancellation of Sale Deed

First of all tell me whether A has any document in his favour to prove his case? If yes, then the transaction between s & c is viod ab initio.

the seller "S" executed a sale deed in his favour.

Since seller S has sold the property to you first through a registered sale deed and then conveying the same property through another sale deed to C, this amounts to cheating for which you said you have already initiated criminal proceedings against the seller.

So far as safegaurding your right to title is considered, i feel you should approach civil court by filing a suit for declaration of title as well asking for the relief of cancellation of sale deed executed subsequently by S to C as null and void.

I do agree with Mr. D.V.RamaKrishna

Yes 'A' can validly through the court of law can cancel the Deed executed in favour of 'C'. This is because the first sale deed too is registered and it was incumbent upon 'C' to enquire about the prevailing title of the property purchased by him. Moreover, S will be also held liable for selling the same property twice. 

Can A execute deed of cancellation before the sub registrar?

open the land reforms act book of your state. look at who does the mutation. then apply to the district land & land reforms officer to rectify the record of rights under section (consult an officer in the land reforms dept about the sections) after proper hearing the mutation of the other party will be cancelled and the record of rights shall be rectified. see that the possession of the land is with you. simultaneously proceed with the criminal proceedings as others have suggested. also go through your sale deed and thoroughly see if there are any loopholes left out.

open the land reforms act book of your state. look at who does the mutation. then apply to the district land & land reforms officer to rectify the record of rights under section (consult an officer in the land reforms dept about the sections) after proper hearing the mutation of the other party will be cancelled and the record of rights shall be rectified. see that the possession of the land is with you. simultaneously proceed with the criminal proceedings as others have suggested. also go through your sale deed and thoroughly see if there are any loopholes left out.

IF we sold same property(flat) twice to a and b by mistake. so what we have to do for save our points. 

How can A execute deed of cancellation?.  A is thrid party to the sale deed between S and C.  The only remedy is approaching the court for cancellation of sale deed between S and C save filing of criminal case against S by A.

A can apply for cancellation of his sale deed.  Then automatically the C's sale deed holds good for C.  This can be done at Registrar office itself.

Sorry the my first respose was a mistake because i read the question requirement wrongly. 

Thakns

Mr. Rao