Bachelors

In India, you have limitless opportunities if you have done your Masters in Geography. Geography is a very vast and diverse combination of many subjects. In this course, you have to study and analyze spatial phenomena, land management, conservation, resource management and extraction, urban planning, development work, etc. Hence with these skills and command on subject matter one can apply for ES SO (Earth System Science Organisation). There is good demand for the faculty posts too. Other than this many government vacancies are available in different departments like forest services, petroleum industries, etc. The best option is teaching where you can pursue PhD and earn a big chunk of money simultaneously. But again, the opportunities also depend upon 'your quality'. How and from where you pursued your course also matters. So, try to be focused on learning about career and job opportunities as well.
Best of luck.

There are quite number of opportunities present in the working world today for students from this field. You will be presented with the option of joining education, government, non-profit sectors once you complete your education in this field.
There are a number of benefits of studying the subject, as a Philosopher will develop reasoned arguments, will communicate effectively also will have the ability to speak, think and write more clearly. Philosophers are known to have more creative and original solutions to problems and can easily analyze complex problems as well as examine problems systematically. Also, philosophers tend to learn to be empathetic and also understand related disciplines.
Eligibility
In order to be eligible for admission to a Bachelor degree, one must clear his or her higher secondary school certificate education from a recognized college. The duration for Bachelor course is three years.
The eligibility criterion for admission master course in Philosophy is holding a Bachelor degree in any stream. The duration of the master course is mostly two years.
Course available in Philosophy are
Bachelor of Arts in Philosophy
Bachelor of Arts Honors in Philosophy
Master of Arts in Philosophy
Master of Arts Honors in Philosophy
Master of philosophy in Philosophy
Doctor of Philosophy in Philosophy
Specializations available in Philosophy are
Epistemology
Logic
Ethics
Political Philosophy
Aesthetics
Philosophy of Language
Philosophy of Mind
Metaphysics
Job prospects
A student who completes their education with a Bachelor or Master degree in Philosophy can think of working in quite a number of avenues, both in India and abroad. One can look for a job in many sectors which can range from specialist in HR, interviewer, consultant, student affairs, public service, journalism, research, law, diplomacy, insurance, etc. Students who have done research on philosophy can opt for teaching jobs in research institutes, universities and in colleges.

Yes! It is absolutely possible to change the specialisation even after doing under-graduation from a particular stream. Universities allows but this transition generally degrade your value in the market. Suppose, you have done your under graduation in specialisation in Economics (Say, BA Economics), but now you want to change for Political Science (Say, MA Political Science), university will definitely allows this. Some university ask for particular entrance exam for PG and some may not. But this transition is possible. However, I'd not recommend to change in specialization because due to this change you lacks in "in-depth knowledge (or core knowledge)" of particular subject. Hence it is advisable to continue in your stream. According to me the best combination in UG-PG course is BA-MA in Economics (specially when it comes to Humanities section). The reason that why I am suggesting you this combination is, its market demand and future prospects. Currently, because of the ongoing economic activity in India, the need of economist is exponentially high and it is supposed to increase in near future as well. Hope this helps.
Best of Luck.

If you are pursuing political science then you must be a UPSC aspirant. Political science course in itself is so vast that if you focus on it, you will not require any parallel course. But if you are aiming for UPSC then I would refer you some books that you should read that would increase your insight and at the same time prepare you for UPSC examinations. The first one is Indian Polity by M. Laxmikanth and the second is India's Struggle for Independence by Bipin Chandra. The book Indian Polity is considered the bible for UPSC exams as there are approx 25 questions you will get in that exam from Indian Polity for sure. On the other hand, India's struggle for independence is also an important book which enlightens you about the facts and all the hard work India went through to attain independence. If you are a first-year student, I would recommend you to start taking general studies coaching from your second year.
If you do these things, you won't need any other parallel course while doing political science.

I am not sure about physics, but surely you can combine maths with your humanities subject. If you have economics in your humanities subject then maths as an additional subject can definitely prove to be a boom for you. Knowledge of core mathematics is highly necessary for understanding the advance theorems of Marco-Micro economics. When it comes to the understanding the concept of consumers producer behaviours, price determination, revenue recognition, etc., you must have the knowledge of matrices, differentiation & integration, statistics and probability. These concepts help a lot while having an advanced and realistic knowledge of economics (as a part of humanities). So, in this way, we can relate the subjects of maths and economics. Here, physics may not help you much (since physics is the application of mathematics in the practical world), but it may help you to enhance your mathematical calculation skills. Hope this helps.
Best of luck.