hey nandu 

you might not get government college with 300 marks beloning to ST category in telangana under state quota as previous year minimum cut off of telangan for the same was 406 of government medical college in siddipet. dont lose hope you can get dental colleges or collegs in other state. visit follwoing link to predict colleges on the basis of your neet marks https://medicine.careers360.com/neet-college-predictor?icn=neet_clgpd_landing_page&ici=clevertap-sticky-web# 

goodluck