Father purchased a property but unable to pay registration fee

Respected sir recently ( last year 2017 dec) my father (62 years old) purchased new flat on his name now it is in under construction, my father took 10 lakhs loan from bank, now dad want to transfer his property to his son, for that registration again they are asking 2.80 lakhs, now my father and his son don't have the capacity to pay that registration amount. both are govt employee's only... please suggest me