Removing fathers name from Agreement for sale

I entered into an agreement for purchase of flat in Navi Mumbai Panvel on 10th June 2022 with builder, I had included myself and father's name into the agreement for sale. I work in a public sector bank where we get a benefit of interest rate over public rate. Now while availing the Housing loan I have been asked by my bank that since fathers name is included in the agreement for sale, Housing loan can only be availed in public interest rates wherein I won't get any benefit as staff. I want to remove my fathers name from the agreement for sale and proceed with Housing loan to avail staff benefits. What should I do, I have already paid the stamp duty to Maharashtra government. How to proceed ahead.My bank has said to do Housing loan at public rate and after possession letter is received to arrange a gift deed through my father where he revokes all his rights fro the property. But since possession will take a long time atleast more than 1 year, I have to bear huge interest rate difference. How do I avail the Housing loan as staff by removing his name from agreement for sale which he agrees to without any conditions sincse he understands the gravity of the situation. Kindly help .