@ rajesh, i second the opinions of nalapani. the khas from gandaki region and eastwards have been hinduised thoroughly and spread out after the disintregation of khas empire post 12-13th century. and the khas of karnali also took hinduistic rituals but they still follow their shamanistic dewali,masto and kulpuja traditions. the khas eastwards of bheri river dont do that generally and are culturally more and more getting closer to indian high caste rituals.

@ magorkhe, thakuri may have been a ruler post as mahat, rai or subba .there are some thakuris who look aryan and some clearly look mongoloid.since west of kali there were also other petty kingdoms called 12 thakurai and in indian mainland too there were thakurs who were petty chieftans .the thakuris of gandaki region are either magar or mix of khas and magar and their religious and cultural proximity to both these big ethnicities made them easy to combine their forces and go on for unification.
पातकी बाहुन हरुले आफुलाई सबै भन्दा माथि राखे |...-pre-rana regime ,the social fabric of nepal was not like that we imagine today . caste system as concieved in indian heartland never existed in nepal, it was peculiarly nepali in our hills.but thats not our topic today