Government & Defence Entrance Exam

ISRO publishes requirement for the post of Scientific Officers at regular interval. You are advised to review ISRO website regularly for all jobs which has eligibility requirement of MSc Physics. Refer http://www.isro.gov.in/careers

Firstly, make you physics and maths strong for the written test. Start reading newspaper to get knowledge about current affairs. General knowledge portion is scoring one, so make sure you get good score in that.
Solve last year question papers and refer to books available for entrance exam of air force and railways.

Hello,
This is true that you can fight for both the exams at the same time.
Syllabus of both the exam is quite similar.
There are many coaching like:
1. National Banking Academy (NDA)
2. IICE Institute
3. Smritee Institute - Best SSC Coaching
To know more about the SSC exams visit:
https://www.eduncle.com/ssc-cgl-recruitment-exam
You can also go for the self-studies to clear the competitive exams like these, all you need a proper dedication and good reference books.

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There, you can know more about NDA Application details.

Please Visit This Link: https://www.entranceexamcds.com/recruitment-exam-cds/SSC-Postal-or-Sorting-Assistant
There, you can know more about Postal Assistant Preparation Materials.

Hello,
The minimum education Qualification requirement is a graduation degree in any of the discipline.
You need to appear for SSC CGL exam and score well.
After cracking SSC CGL exam you may become Income tax inspector. Soon after few years you will be promoted as Income tax officer.

B.Tech graduates can join Indian Air Force as Flying Officer in Flying Branch and Aeronautical Engineer in Technical Branch. Combined Defence Services Examination (CDSE), Flying (Pilot) Short Service Commission and National Cadet Corps Special Entry are three modes through which B.Tech graduates can join Flying Branch. Direct Entry Scheme and University Entry Scheme (UES) are two entry options available for aspirants to join the Technical Branch in Indian Air Force.

Don't place your self in any sort of confusion. Go with B.Com & alongside keep preparing for the UPSC exam.
All the best.

If you want to become an IAS officer, you better choose BA as it will help you in your preparations a lot. Choose economics as your honor and keep in touch with the current events. Go through the newspaper everyday and read magazines regularly as it will boost up your general ability as well as brush up your vocabulary skills. History, geography and political science are the subjects that you will be taught in BA. If you choose other options like B.Tech, then it will be a little difficult for you.