Implication of borrowing money from blood relation to pay back home loan

I have a home loan of 30 lakh from HDFC. To pay off the loan, I plan to borrow ( @ 8% PA) from my real brother. I plan to pay back to my brother over the next 5 years. I have following queries on this - 

1. What are the necessary documentation that should be done to ensure, no Tax implication on my brother for principal amount I will pay back?
2. Would I be eligible for tax benefits for home loan?

Any other precaution that I should take?

Thanks in advance.