Can I do masters in Bioelectronics after doing BTech in Electronics and Communication Engineering and from where I can do it (options from India and abroad)?
Ofcourse you can!!
Appear for GRE. Prepare well and go for it.
When there is a will, there is always a way. It shows you have interest in electronics. There can't be anything better than studying subjects you have interest in.
Top Universities from where you can pursue MS in Electronics are:-
University of Cambridge
University of Oxford
Imperial College, London
ETH Zurich
KTH Royal Institute of Technology
MIP Milano.
Just you need is to score exceptionally well in exams like GRE, TOEFL and enhance your communication skills as much as you can.