I disagree as nepotism has multiple axes
What describes nepotism best in India? A poll
Let's take a case...
Suppose you are a Tamil brahmin hiring manager in Delhi
Are you likelier to have a soft-corner for a fellow Tamil Non Brahmin from your native town?
Or a Delhi-based Hindi speaking brahmin?
I think Language trumps caste
Would a Bihari Brahmin hiring manager likelier to have a rapport with a fellow Bihari Kayastha or Yadav?
Or a brahmin from Western UP?