What do you mean by how much money?
If you look at the open interest of a contract, it tells you how many lots are currently open. If you know the margin required for 1 lot, you can multiply to find the total margin blocked currently for that contract.
So if you see OI as 10000, lot size is 100. (assume future price is 100).
So that means 10lks futures on buy side and 10lk futures on sellside is open. So total 20lks x 100 = Rs 20 crores of futures are still open. If SPAN margin for this is 20%, that means Rs 4 crores is the money blocked currently for this position.
Perfect. Thanks. Just wanted to find out how much money people are putting in that one contract.