Hi, 

There is no particular limit as to how many colleges you can fill in your choices during the counselling process. The colleges where you think you have a chance fill them first followed by those where chances are comparatively less. 

If your score is 175 then i am sorry but its difficult to get a mbbs seat this year. You can try in deemed universities like laxmi narayan, arupadai veedu medical college, sri rachandra etc. You might have a chance there. But a fact to consider is that the fees would be high for these colleges. Around 20-22lakh/annum.

I shall attach a link below which might help:

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