I have been studying for an MSc in chemistry from IIT Hyderabad, but my 12 marks are just 61.5%. Will I qualify for a PhD abroad?

For a PhD, class 12th marks are given considerably less importance given that your graduation and post-graduation grades are great.

For a Ph.D. abroad, since you will be seeking direct admission into the university and not approaching a specific professor, your past academics matter a lot. Having good class 12 marks, graduation, and post-graduation marks will improve your chances of admission and it’s always better to play safe.

In case of average marks, you have the option to write to a professor in Europe who is working in a field that aligns with your research project topic. If you share a common ground with any professor you can get admission by skipping the entire formal admission procedure although you might have to appear for some interviews that will evaluate your research caliber.

Overall, my recommendation is to apply everywhere as long as money is not involved. In cases you are required to send documents or GRE scores you need to be careful.