you are right Raju161 but we don't have lot of knowledge about these defeat, how were they defeated,
and what happens to them and their descendants.
We also need to know the Kiratas contribution in every aspects of life in Ancient India and Nepal thoroughly
and their influences and religious practices in the early period
Raju not much of Kiratas has been mentioned, published or studied in Nepal. Or it can be simply correct to say
it has been neglected.
As you know without tracing back the Nepal roots and origins, we will lose a great deal of  history and culture
of Nepal and its people.
Foreign influence results and your identity will be eradicated once and for all.

Now that is sad. Very sad i have to say.

That's why i am doing research on Kiratas, their contributions to the history and culture of India and Nepal.

There are many scholars who are also doing this research and some of it have been published recently are;

Politics of Culture: A Study of Three Kirata Communities in the Eastern Himalayas
By Tanka Bahadur Subba (1999)


History and Culture of the Kirat People: Part I-II
By Cemjonga, Imana Simha
Published by Kirat Yakthung Chumlung, 2003
Original from the University of Michigan


Bharavi's Poem Kiratarjuniya or Arjuna's Combat with the Kirat by  Bharavi, Carl Cappeller (Translator)
 Publisher: Kessinger Publishing Company, 2007
 
KIRATA-JANA-KRTI by Suniti Kumar Chatterji, 2007

I will update more once i have done readings and research.

SKH