Many thanks for the answer,
Please follow the link given bellow,
Your U.S. Tax Return: U.S. Tax Treaties for Professors, Teachers and Researchers
And see the lines bellow... present in the above link,
India
An individual is exempt from U.S. tax on income received for teaching or research if he or she:
*Is a resident of India immediately before visiting the United States, and
*Is in the United States to teach or engage in research at an accredited university or other recognized educational institution in the United States for a period not longer than 2 years.
If the individual's visit to the United States exceeds 2 years, the exemption is lost for the entire visit.
This exemption does not apply to income from research carried on mainly for the private benefit of any person rather than in the public interest.
I would like to now what kind of "2 years" is that..
Like two calender years
Or
Within two years from J1 arrival to USA.
Thanks..