I came to US in dec 2010 at that time my son had J2 visa but he was in India. He is coming in June 2011, can I claim him as my dependent in 2011 tax fillings.

As you are a non-resident alien, you can not claim any dependents.
If you are married to a resident alien you can choose to be treated as one as well and file a joint return. In that case you could claim your child as dependent