Dear Syed,

The exact answer for this question is not possible due to massive fluctuations between cutoffs from different years but you can estimate the score requiredd by using the following tools-

https://www.careers360.com/result-predictor

and 

https://medicine.careers360.com/neet-ug-college-predictor

If you hail from a reserved category or a state with many goverment medical colleges you might even have a chance in governement medical college. To be honest after the formation of NEET all the seats are controlled by STATE DMER OFFICES and college has no means to interference so please don't fall into a trap or any one promising you a seat in exchange for hefty donations.

Apart from that  450+ is Actually a pretty good mark for deemed or private medical colleges. you must use the predictor tool to understand where you stand.

All the best Syed!