Answer : 1. "Larsen and Toubro"
Explanation :

Solution: Indian officials have opted to retain the use of American Cummins engines for the entire Zoravar Light Tank project. Originally, the project was intended to incorporate a German engine, but faced delays due to the lack of German export control clearance, known as BAFA clearance. As a result, it was decided to proceed with the American engine. Zoravar Light Tank is a cooperative initiative between DRDO and commercial company Larsen & Toubro.