Find Scheduling algorithm. Adding FSFC(first come first serve) in it

I want to find an existing scheduling algo in openwrt and read it. It will be there from the start, or I need to install it in the source code. Any one know how to do that?

It will be a great help for me. I also wanna ask if it's okay if you know the steps to do that then suggest step's that I can follow.

I guess you are referring to the network scheduler, right? That is part of the Linux kernel and, while the Linux kernel is a fundamental piece of OpenWrt, I think you will obtain much better info and support in the Linux forums.

I think this page can be a good starting point: