Both films did exceptionally well at the box-office.
South Indian films - well, the successful ones - were a litmus tests for producers to recreate for a pan-Indian audience (the Hindi speaking belt). The notion that if it works in a smaller market, in limited screens, it could do well nationwide.
This formula worked well throughout the early 1980s - and now, in 2021, you see many Tamil and Telugu remakes being made in Bollywood. To varying degrees of success.