Don't think it would changed a thing. The PRC was kept out of the UN. What's India seating instead of the ROC going to change that?you are right office and Indians at that time had helped the Empire win 2 fronts in ww2, 5 million Indians died in ww2 ,it would have made for a much better and more balanced UNSC if Nehru had accepted, and many of the rogue nations supported by China would not have been so emboldened with their nukes freely proliferated by China(n. korea,pakistan,Iran).
Incidently, the only proliferation done by the CCP was to Pakistan. Pakistan is responsbile for Iran and Lybia. North Korea program was homegrown.