eBay sells to people world-wide, and you could have operated this business from India, so you could make the argument that the income is NOT effectively connected to the U.S.
However, your activity is a self-employment activity, so the time is 89 days (which you HAVE exceeded), not 183 days. So it IS likely that you need to at least file a tax return on the income earned while you were in the U.S.
However, you are paying income taxes to india on that money as well, you can claim a credit against the U.S. taxes for the India taxes paid. Combined that with your $3,300 personal exemption and it is possible that no taxes will be due.
You will need to file Form 1040NR with a Schedule C and Form 1116, not an easy form to file. I can help you file these return if you wish; just contact me at
[email protected].