What is law of double taxatio of tax between india & usa

Yes. If you have income from India while filing as a resident alien in the U.S. you must declare that Indian income on your tax return, but can claim a Foreign Tax Credit to at least partially offset the taxes paid on the Indian income.

If you are filing dual-status, you do not even report the Indian income on the dual-status return if the income was earned while in non-resident status.