I might go to USA from India for about two/three months (to carry out some collaborative research). As I understand, I might opt for J1 visa, and under tax treaty between USA/India, I perhaps don't have to pay any tax (even if someone pays, he usually gets back the check). But then on my return I may have to pay tax on my savings in USA (though not so sure about this), which I would prefer to avoid. So I wanted to go with a visa with which I can pay my tax in USA itself and come back to India without any tax obligation. I don't know if it makes sense. Kindly advise.

If you are under a J-1 visa, you are a non-resident alien and thus the interest earned on the savings account is tax-exempt.

Go with the J1 visa.