Dear Sir,
I gave the friendly loan to one of my friend on interest in the presence of my relative and one of my friend but in this regard, I did not take any cheque or any document from him. He was agreed to return the said amount within 6 months but he assured me that he will pay the interest till then regularly. But he paid the interest of 2 months. when i asked about the interest he told me that his financial condition is not fine but he will return the principal within 8 months. I agreed with the same. when after passing 8 months, I asked about my principal, he denied to return the same and infact he threatened me if I demand for money, he will file a case against me. Now I need your help. please suggest me the appropriate help or remedy. Can i file a criminal case against him. He breach my trust and cheat me.

Ofcourse you can ask for your money. Especially, when there were two witnesses present when the transaction took place. Further try to accumulate more proofs like his depositing amont in your bank account i.e. the interest, Or matching transactions like your taking out the money from the bank and his deposting the money into the bank etc. That will not be full proof but it will help.

Further talk to some lawyer and initiate some action.