Sale deed against sale agreement

I have purchased a piece of land for rs. 52,50,000/- and made an unregistered agreement on 07-2-2018 and paid rs. 10 lakh through bank cheque to the seller, this agreement valid till [deleted]. i have managed the balance amount and want to do the sale deed on [deleted]. I called up to the seller on [deleted] through the broker to do the sale deed, but the seller did not come for sale deed as demanding rs. 28 lakh in black as hard cash, due to condition of cash in India i am unable to arrange the cash, i want pay the balance amount through bank cheques in white, but the seller is not agree to do that. My agreement date going to expiring on [deleted] and the agreement is not a registered but notorised . i have already issued a notice through my lawyer on [deleted], but after receiving the notice seller still stand on demand of cash. What are my right as buyer? Can i approach to sub-registrar to sale deed? Kindly help and guide me on the subject. my email and contact no are as below :- my email is - [deleted] phone - [deleted] Thanking you, Mahipal Bisht