@Ankur1014 Oneshot is a protocol used to communicate with the ESC. Here is a good explanation of what Oneshot is
From the article:
An ESC protocol is used to communicate between FC (flight controller) and ESC (electronics speed controller), to control motor rotation speed. Originally this is based on servo position protocols, which is a PWM signal between the values of 1000ms and 2000ms (0% to 100% throttle). But PWM is a relatively slow protocol, and susceptible to jitter, and that’s why Oneshot125 is introduced.