I have 1 multimeter which could measure duty cycle of pulse width moduled wave.
Could anyone knows bout it ?

just use voltage measurement

example :

if your supply is 5 v

- if it is 50% duty cycle - voltage will show 2.5V - simple !

Wow . Didnt knew that.
What  if the pwm is from a rc reciever

Pwm width from RC receiver is about 2050uS(max) and varies from 1000 uS to 2000 uS.So theoretically it has to work.