Thank you everyone for sharing your experiences/ inputs. I really appreciate!

I should start doing tit-for-tat. I from today start to completely ignore him. I did quite a bit of introspection to assess if I had any problem. I did not see any apparent one. He uses two completely different tones to talk to juniors and seniors and resorts to mute mode with me :). We work on different projects but in the same department. Recently, my job responsibilities changed and I work more independently and mentor others. He also mentors others. Both of us are two of the best workers there. I do not have any issue with him and do not have any insecurity/ inferiority issue. I do not take Indians to be superior or inferior to a Nepali or any other race/ nationality for that matter. It is just a strange feeling seeing him behave that way. I had many good Indian friends in school and did not have any problem. May be he is little afraid of the fact that I am getting a little share of spotlight he once fully had. I mostly do not work to be in the spotlight. He is taking me for a competitor, which I am not.

Thanks to you folks one more time.