The Indian Army has about 300 Major Generals in its senior leadership cadre, according to a publicly available summary of serving generals.

Context

That same source says the Army has 2 Generals, almost 90 Lieutenant Generals, about 300 Major Generals, and about 1,200 Brigadiers in a 43,000-strong officer cadre.

Note

This figure is an approximate, snapshot-style count and can change with promotions, retirements, and restructuring.

TL;DR: roughly 300 Major Generals serve in the Indian Army.