There are plenty of options if you go with Msc in Mathematics, you can get jobs at startups and top IT companies into data analysis roles and data statistics role with organization like Bloomberg, MSCI, DE shaw which regularly recruit candidates for statistical roles.
With Mscin chemistry, you have variety of technical roles in Pharmaceutical sector like Research and Development Analytics, Data Analysis, Product management, International Sales , etc.
Both have got various opportunities.
You should target IISc Bangalore which has been widely recommended for Placements and its brand reputation.