Property Dispute with Brother

Dear Sir, In Year 2013, my elder brother requires a sum of rs 24 Lacks against the home where we live now. This property is on our name only, he approach a Private Financer and lend money from him. My only regret is that i signed on those papers as a help of brother. But he is not paying the EMI's on time and now in year 2019, he is saying that i would like to sell my part. Now the total sum for amount is 38 lacks (include interest) which now i need to pay to that Financer, as a matter that i am purchasing his half part, and brother is agreed to do the registration on my name. Now my problem that i don't have a believe on him reason: 1. Finance force me to pay 28 lacks in advance 2. If after paying the advance payment of 28 lacks, he (brother) did not turn up for registration of the property. So can you please guide me what precautions or kind of paper work required from my end to insure that again I would not be turned into any trouble. Looking for your help and support on this. Regards.