i have got 6906 rank in jee advanced and 29199 rank in jee main .So si please suggest what would be best for me choossing iit or nit

No prediction can be made about  NITs/IIITs, you better visit the official weblink of Jeemains or Josaa, if you made it there, well adn good, otherwise you can surely try your luck at some other renowned and highly esteemed institutions across the country,.....mind you, these institutions are no less in any regard than IITs/NITs/IIITs...may it be a matter of quality education, better infrastructure, ultra-modern teaching pedagogy, best ever placements or handsome pay packages........I suggest to visit the websites of these institutions in order to gather an extensive information about admission process – Manav Rachna College of Engg, Faridabad,......................Lovely Professional Uni, Phagwara,.........................PES Uni, Bangalore,..............Jadavpur Uni, Kolkata