How to reset my lenovo r61i supervisor password

you can -
try to remember the password.
use a password reset disk to reset the password.

See this sticky topic for that frequently asked question:
LOCKED OUT OF YOUR LAPTOP?

Dont use stolen Laptop.

We can't provide assistance with by-passing/cracking any password protection, as we can't verify ownership of the system.
You will need to contact the vendor or the manufacturer with proof of ownership/purchase and they will be able to help.
Good luck.