I see that you have got AIR 1769 and OBC category rank 606 in NIMCET . You want to join IPU . Listen IPU had been accepting only scores of IPU-CET till last year. And from this year they started accepting NIMCET scores . So basically their is no such previous record of cutoff ranks of NIMCET for IPU from which we could have predicted your chances. But considering your rank it might be possible for you to get a seat in IPU. 

All the best.