Which course should I pursue to get good salary package, M.Tech or MBA in biotechnology?

MBA is a better option as compared to M.Tech. But it also depends on your area of interest. First, understand that in which field you are interested, if it's MBA know whether you can cope up with the syllabus and move forward do the same for M.Tech. Then get a conclusion. All the best.

MBA is a better option to go for if you are comparing pay scales. M.Tech has limited options after degree completion whereas MBA in any specialisation of your choice (marketing/finance/HR) will open numerous options for you.