Equvalent Grade to 30CrNiMo8
OK, I'm confused. Why not just ask for 30CrNiMo8? You know, Werkstoff Number 1.6580? Are people telling you "No, we can't get that, but we can get something close" and then try to sell you carbon steel?
The composition is 0.26-0.33 C, 0.70-1.10 Mn, 0.04 P, 0.04 S, 0.15-0.40 Si, 1.80-2.20 Cr, 1.80-2.20 Ni, 0.30-0.50 Mo, base Fe, so you see it is a medium carbon steel with good hardenability, rather like a 4330 steel in the North American nomenclature. You need to decide what it is you want, and then try to buy that in India.
Also, please remember that 30CrNiMo8 is just a composition. You can buy it as bar, sheet, plate, cast blocks that would be full of shrinkage porosity, or pressed together chunks of machining chips. You would be very wise to consider using a real specification, rather than just a composition designation, to specify your parts.