We can start by reaching out. Something similar seems likely to happen between the US and North Korea. The Taliban doesn't have a deep-rooted problem with India. Moreover, it is isolated and weak. Diplomatically, we will also undercut Pakistan, which is in any case not in a position to compete with India in offering economic inducements.
Diplomatic recognition is secondary.
India does not recognise Taiwan as a sovereign state, but we have extensive economic relations with it. Even if we choose to postpone a fully formalised relationship with the Taliban, the economic option remains a pragmatic and useful one. If the Taliban regime continues to be isolated and squeezed, it will stay embedded in an amalgam of arms, drugs, radicalism and terror. If we can help it break out even in a small way, we can serve our security interests better. A policy of engagement will cost us little, and perhaps bring us more gain than we expect.