i tried to find any clue about the tegra tx1 pwm pins , any help
Assuming you want to drive servos, check out this excellent link:
actually i need the pwm pin which is provided at http://elinux.org/Jetson/PWM
so if i need this pin location on tx1 carrier board from where could i get it ???
This article and the eLinux wiki link you gave both recommend against using the PWM pins, is there a reason why you specifically need the onboard pins?
If you have to have the pins, they should be in the schematics: http://developer.nvidia.com/embedded/dlc/jetson-tx1-developer-kit-carrier-board-design-files
You can find that doc and the other docs on the embedded downloads page: https://developer.nvidia.com/embedded/downloads