DRDO released a statement which said, “In comparison to the existing Akash System, Akash Prime is equipped with an indigenous active Radio Frequency (RF) seeker ... Kub (SA-6 Gainful) missile ...

The 9K37 Buk is a surface-to-air guided missile system developed in the late 1970s. The weapon was indeed constructed in 1979 to replace the aging 2K12 Kub system from the previous decade.