Your challenge is to leave another legacy of colonialism in India. You need to some how create a large British community in what is now the independent nations of India, Pakistan and BD.
This community should be large say several million people. Which is large enough to ve viable and distinct. History should follow OTL as nearly as possible, meaning Independence should come as it did and so should partition although the forms of the above can be different.
So, how do you do it.