Dear Student, yes the degree will be valid even if you join the job. But you will have to transfer the course from regular to distance mode.
One caution however – if you get a regular graduation degree, the options after it are huge. Eg., if you want to take admission for MA/ M.Sc courses, you will have a better chance to get through. Or job wise too, you will be at an advantage if you have procured your studies in the regular mode. But that’s your call. Since you are joining a government job, we advise you to find out about promotion prospects etc.