From your informations, it comes out :-
1.Your father transferred some land to your relative who was of creditworthy nature.
2.You relative mortagaged the land to the bank and a loan of Rs.6.5 Lakhs was taken in the name of your relative.
3.Your relative kept Rs.2.00 Lakhs out of the loan and passed off the balance Rs.4.5 Lakhs to your father.
4. You relative and your father are paying the instalments in proportions i.e. Rs.2 Lakhs and Rs.4.5 Lakh.Now your relative wants to return Rs.2.00 Lakh to your father. This means that entire loan is to be paid by your father.
5.And finally, the land which is now in the name of your relative is mortgaged to the Bank.
And now you want the loan to be transferred to your fathers name. The mortagaged Land is in the name of your Relative now.
Please confirm whether the above facts are correct.
From the brief information you have given, even if the entire loan is transferred to your father, he will not become the owner of the land which has been mortagaged as it is in the name(?) of your relative.
But anyway first confirm the above reading of he case.