Northwest and KLM miles can be used on Jet Airways.

Air France Frequence Plus miles can be used on Indian Airlines and Air India.

From November, I believe Lufthansa Miles and More miles should be able to be used on Air India.

The 4 Indian carriers all have their own programs too. AI/IC run "Flying Returns", 9W has "Jet Priviledge" and S2 has "Cosmos".