Complex sentence: Konok Thengra was a great astrologer and his great contribution was the prominent Kaibaron Puya, which depicted the future of Royal life and country's fortune, and it had witness with real phenomenon in the history of Meitrabak (i.e. Manipur).
Split into simpler sentences: Konok Thengra was an astrologer, and his great contribution was the prominent "Kaibaron Puya", which depicted the future of Royal life and country's fortune. It had witness with real phenomena in the history of Meitrabak (i.e. Manipur).