Currently I am on H1. Can I file returns for my social security with hold, medicare money.

Negative. You became liable to pay Social Security and Medicare taxes the day your H-1 visa was approved. These taxes are flat taxes that are withheld directly from your paycheck.

There IS a cap on Social Security taxes. The income limit is $94,000 for 2006 and $97,000 for 2007. If you work in two jobs whose combined salary exceed $97,000, then you can request a refund for the excess Social Security withheld on the back of Form 1040.