hi,

see when you complete your bachelors you are eligible to apply for jobs which requires of bachelors degree and since you are from physics background you may apply for lab assistant work in schools or degree colleges, may apply for teachers position, bank , po job etc. however you may not do full time job if you want to do msc course in full time. however you have to decide now , for full time msc course you may work as part time, or if you need full time job you may do msc course in distance or part time mode from IGNOU or other relevant university.