Kamov Ka-28 Helix-A, and the Kamov Ka-31 Helix-B: The KA-25 was acquired by the Indian Navy in 1980 for anti-submarine warfare, but had severe technological limitations.
The KA-28 were acquired in the mid-80s, and were said to be a quantum leap over their predecessors from an ASW standpoint. The KA-31takes the Kamov capabilities even further by enabling real-time network-centric warfare for the Indian Navy.