I am a Tamil myself, and am deeply offended that India wont defend the interests of Sri Lankan Tamils, because they are Tamils.
There were Gujjus being kicked out of Uganda, and Indians being kicked out of Fiji. I did not hear anything about India arming or helping them in any way, eventhough by your definition, they are "north indians".
The fact is that India has already done more than its share for the Sri Lankan Tamils. It continues to host them in TN. Support for LTTE is not the same as support for Tamils.
Further, SL Tamils are Sri Lankans, not Indians. Any help we offer them should be on moral and humanitarian grounds. Not political or ethnic grounds.