Defaulting in payment of loan amount lent to a family member

Dear Sir, One of my distant relative took 5 lakhs from me in and around 2012-13 and paid interest on it for few months. After that he cited various reasons of losses and stopped paying interest and told me to waive off interest and he will pay the principal amount only. I agreed as I wanted to recover my money badly. For the last 2 years he is not paying interest and giving various excuses and delaying to pay the principal amount. Everytime He is just keep on extending the payment date for few more months. As the loan was given in terms of family relationship purely on the basis of faith and helping him, which has now been a burden on me. So in that case how I can I initiate action against him to get back my money.