2- What does means to declare spise world wide income if filling married jointly? Declaring means I ha e pay to pax in USA or if I paid tax on her income in India then only I have to declare in USA but no need to pay tax in USA, is it true statement?
The title/subject of your post, apparently has absolutely nothing to do with the content/body of your post.
When filing a U.S. tax return you must report/claim all income from all sources on the entire planet. Period. You will pay the IRS taxes on that income, no matter where that income was earned. Now if you paid taxes on any of that income to a foreign taxing authority, then you will be "credited" for taxes paid to a foreign taxing authority. That credit may or may not be dollar for dollar. It depends on what type of reciprocal tax agreement the U.S. may have with the foreign taxing authority you paid taxes too.