Hello,

This depend upon how you effectively you can manage time, As you can see there are many who prepare for their exams when they are working or attending their college. They have to put in some extra effort, wake up early or for some sit late in the night and prepare. It is possible to prepare when you are doing your course. I would suggest that instead of fixing the number of hours, you should fix a tooic and try to finish that before you sleep. Mittali Sethi was working as an orthodontist when she cleared the exam. Mr GSS Praveen Chand  had prepared for CSE while working as a Tech Lead in a software company for three years. So it is possible provided that you have dedication for it.

Good Luck