To get original certificates back

Iam a doctor(MBBS) completed n practicing for 7 yrs now. I had asked one man(who is a distinct relative of mine) to enquire for a pg seat for me. Suddenly next day itself that man called me up and said to get ready to go with him for a seat enquiry and it was very important to go on tat day. I took my car and went to him.After he got in, he said another 2 men are coming with us to Mangalore.I took them also and left to Mangalore KS Hegde medical academy. There outside they said another one man is waiting for us, and that man is the one who will.help.us with the procedure for admission. We went into tat man's office and we had a discussion, which was He said 1.8Cr for the pg seat in general medicine. And its the best college there. And the seat is very demanding and if I need it, I have to.block it that day itself. Blocking by keeping my original certificates. I thot I shud block and said ok. That mangalore man took me to the college administration office and I submitted my certificates there in the office. I did tat as I was scared that I might loose tat seat. This happened on May 6 And as I was registering for NRI seat They wanted my dad's nri papers...which I dint have at that tym. They asked me to submit tjose papers by May 8th 5pm. Which I couldnt. As my dad told.me he wont be able to pay that huge amount. And also making those papers will take more tym.too. So on May 8th I called up the person from mangalore and said the fact that I wont be able to join as my financial background is not allowing that. From that moment the mangalore man is yelling at me and now he is telling me never to go to the hospital and also he will not give my certificates back without giving him 4 lakhhs compensation. Am asking you all is there any rule like this??? Is there any way that i can get my original certificates?? That mangalore man is saying that Am already an admitted candidate.. But I never understand how without completing all the procedures Iam admitted there.. Please help.