I was on L1 in USA in the year 2010. My wife and one kid(12 months old) was also with me. Me and wife has SSN but my don't have ITIN. Now I move to india permanently and I need to file tax return for the year 2010.
Please suggest me the last date to file tax return and how should I file tax return for the year 2010 so that I can get benefit of my child too.

If I will file return after March 2011, so should I need to pay additional charges for late filing.

Thanks

You can file paper return from India and give your India address. What return you will file will depend upon:
When did you enter US on L1? Did you file 2009 tax return?
When did you leave US?

Due date for filing is April 18, 2011. If you do not owe any tax, you will not pay any interest or penalty if you are late.