Considering that during the Highland clearances Scots went to North America and Australisia you are going to need another factor for them to choose India. Given that Indians are going to be starving it is even less likely that Scots will go there. Darien was a disaster because people lied. During the clearances Scots knew where to go because previous emigrants had sent back letters.Britain more dominated by greedy aristocrats.
Greater social inequality in Britain.
Britain gets stuck in a demographic trap.
Excess population go to India.
Indians starved by greedy aristocrats.
Nasty food riots and ensuing conflict.
Make it easier to get into the civil service if you were half british
More single British men coming over and fewer families and/or having an Indian mistress/wife be more socially acceptable and you can get a decent number of half-British Indians. Change the administration system so that it's more British heavy to help get numbers up. You could also get more British business in...