Hello @Anirudha_Gaikwad
Welcome to the forum.
BTN7960B and the rest of the family such as IFX007Tx have a design limitation where the chip severely overheats at higher than 1kHz (1000Hz) PWM frequency. There are threads on this forum explaining the problem. Also, BTN7960 is an old design which performs even worse than IFX007Tx.
One way to solve your melting problem is to lower the PWM frequency down to no more than 3000 to 5000 Hz at most depending on your duty cycle, and put large heatsinks on the chips. Another way would be to use different drivers, which means you have to create a new board design with different components.
Cheers,
Valentine