Buyer not paying

no need to appraoch the registrar, approach a good lawyer, if there is clause for forefieture of advance mony, you can forefier the money, and you have to send a leagal notice to the intending buyer.

First, U give a possession of the property to the purchaser?  Answer is no. First u give a possession after clear the checques but the checques are clear in 6 months because  Checque velidity is 6 months now 5 month is gone, so u present these checques in your account and give informantion / instruction to the buyer that in case the checques are return the sale deed is cancle and we take a legal action for that. U give this notice by your advocate.

OR

U take a possession of the property and give a possession after clear the checques and i think this type clause written in your sale deed u read it. 

present the cheque immediately, as it is five months already. after it gets returned, file a set-aside petition with the help of your advocate.

Thank you all for your advises, I have presented the cheque in tha Bank