The approximate rank for percentile 43 will be around 498500(+-). Note that this is just an estimation and it can change after JEE Main is again conducted in April depending upon number of students appearing for it.

But in this rank a general category student cannot get any NIT. The rank must be pretty much high. (Cutoffs for other categories cannot be predicted as it depends upon various factors)

You can again apply for JEE Mains Examination happening in April. The best score out of the two exams will be considered so give your best in that exam. 

If you still have any queries feel free to ask in the comment section down below.