Hello Jayesh, 

In MBBS courses,  colleges often ask you to sign a government bond of usually one lakh rupees or so as security money. This is the money you have to pay if you want to suddenly quit your medical course or refuse to do the compulsory internship assigned under the course. You will have to pay the bond money in case you quit because they withold your original class 12 certificate and other such original documents which they will not give back unless you have paid them the security money as prescribed in the bond. 

Hope this helps :)