BDS

It will be next to impossible to get admission to an MBBS in a government college with a score of 394 in NEET because the cut-offs for government medical colleges are usually much higher than this. But there is still some chance of getting admission in BDS, as the cut-off for dental courses is usually lower.

This would improve in case one belongs to any reserved category (SC/ST/OBC). One can also check with private colleges for MBBS or BDS, as this would have a cut-off much lower than that for government colleges. All India and state counseling should also be given a shot to have a better chance.

The BDS students at this College of Dental Sciences get an average placement package of Rs 3 to 5 Lacs per annum. The above pay structure may differ with the type of organization, place, experience, or skills of the applicant. Graduates find employment at private dental practices and clinics, in corporate hospitals or at dental clinics. Also, some students may decide to open their practices, or continue their studies, for example, MDS (Master of Dental Surgery) which may affect the income on the long term then. The placement success is the combination of the university network and the student's performance.

Yes, you have a chance to get into Saveetha with a 450 score in NEET.  450 marks in NEET corresponds to a 3–4?lakh rank in the exam. The cutoff required for admission to BDS in Saveetha ranged between 107,400 to 908,494 for the students belonging to the OBC category.

Dr. BR Ambedkar Medical College, Bangalore
Offers BDS with an average fee of 31.30 lakhs.

Raja Rajeshwari Medical College and Hospital, Bangalore
Provides BDS, MD, MS, DM, MCh, and Ph.D. programs with an average fee of ?1.26 crores.

Ragas Dental College and Hospital, Chennai
Offers BDS, MDS, Ph.D., and Diploma programs with an average fee of ?10 lakhs.

Dr. MGR Educational and Research Institute, Chennai
Provides MBBS with an average fee of ?1.28 crores.

It's unlikely that you'll be able to get admission for BDS, BHMS, or BAMS with 185 marks and a rank of 1052142 in NEET: 

BDS

A score of 400 in NEET gives a fair chance of admission to a BDS course, especially for reserved category candidates. However, to get a seat in a government dental college, a candidate usually needs a minimum score of 450. 

BAMS

For admission to a private college offering a BAMS course, a score of 450 is usually enough. However, for government colleges, a minimum score of around 500 in NEET UG is typically required. 

There is no such system going on currently.

If you have to do mbbs, attend the NEET exam again and do the councelling procedure.

No, candidates cannot join Nair Hospital Dental College Mumbai without NEET for BDS. To get admission, candidates are required to apply and appear for NEET UG. Further, candidates are required to fill out the basic eligiblity i.e pass Class 10 and Class 12 or equivalent with 50% aggregate from a recognised board.