can I get a free mbbs seat if I score 450 in neet ?

Varshitha, there is no concept of free MBBS seat. There are Govt  MBBS Colleges, Private Medical Colleges and Central/Deemed Universities. Private Medical Colleges do not participate in All India Counselling and the seats are filled through State Counselling alone. And for appearing for State Counselling you need to hold the domicile of that particular State. Or else the only other option is through Management Quota. Under All India Quota, All the 15% of All India Quota Seats except for Jammu and Kashmir, 100% Seats at Deemed and Central Universities, IP Quota seats in ESIC Colleges, Seats at AIIMS, JIPMER and AFMC are filled by DGHS. The 85% State Quota and Private Colleges are filled by the respective State Authorities. And there are 3 Categories in Private Medical Colleges. Category A is the Government Quota Seats. And only candidates of the home State are eligible to apply for these seats. B Category seats are also called Management Quota Seats and they are filled through State Counselling and the remaining seats are filled through direct Admissions by contacting the College directly. Here the fees is usually nothing less than 40 lakhs. The last Category is NRI seats Category and you cannot apply for that. So the least expensive seat is a seat in a Government Medical College followed by a Govt. Quota seat in Private Medical College. You haven't mentioned your Category but 450 is tad kess score for a seay in a GMC. You will need atleast 550-575.