If you really want to do research join as a RA at a great professor in your field and work for a year to publish quality papers at conferences and subsequently journals. Apply for a funded MS in the US or Europe, next year.
Maybe you could hit a direct PhD with a great publication.
Is it the end for me and my dreams to build a strong research-oriented career in Computer Science(AI/ML specialization)?
Nah, not at all. Just focus on researching and especially reproducing quality papers and open sourcing the code. You'll be alright!
I too didn't sit for placements. I even didn't write GATE.
Just enjoying life, research, sports and fun!