I am class 11th student and I want to be IAS in future with my optional subject as maths then what should I do from now so that I would not get any difficulty or to get a better rank in IAS written exam with maths as optional
For a good preparation of IAS, you must study the subjects like Economics, Public administration or Political Science and Basic maths.
Since, you are already choosing maths as a optional subject, keep economics and political science in your curriculum as well, for you don't face much difficulty while preparing for IAS.