in which particular field is the best gor msc chemistry?

We can not say that a particular feild offers better scope or have better opportunities than the other for candidates pursuing Msc in Chemistry. It depends on which sector you want to make your career in, which feild of Chemistry are you more insterested and passionate about. Some of the popular sectors which offer career opportunities to Msc graduates are Agriculture, Forensic, Enviornment, Pharmaceuticals, Food Insdustry, Oil and Petroleum sector, Power, Research, Healcare, etc.