Thats really simple....
Thats because no one in India are booking Linkin Park to perform a show for you.
Linkin Park are not asking countries about, to perform a show for them, the countries have to invite them to their country.
yups...there are million of fan in india...check out the tour dates... http://en.wikipedia.org/wiki/A_Thousand_Suns_World_Tour
10 november 2010 india delhi....but they didnt perfomed a concert in india ..