I got 250marks in neet exam 2019,any chance for free seat in sangivalasa nri medical college

Dear Lakshmi, you haven't mentioned your Category. Neverhless, the cut offs for various Categories for NRI college have been as follows:

General Category: 502
LOC-OPEN: 485
SC: 384
ST:340
BC:444

So irrespective of the Category, 250 marks is a less score. Having said that, cut offs change every year and are dependant on various factors like no.of seats available, no.of candidates appearing for the exam, top NEET score and difficulty of the exam. You can also check the cut offs of various different colleges under your category at:
https://medicine.careers360.com/articles/neet-cutoff-ap