It is not possible for me to sleep by 10 pm because of office work. What can I do?

Attempt to adjust your work schedule so that you can finish your work earlier, if possible. This would be the optimal solution.

If that's not possible, try to wind down at the end of your day with a low-stimulation activity, such as taking a hot foot bath, journaling, practicing meditation or yog-nidra, or any other technique that helps you transition out of work mode and into a restful state. This will help to relax your nervous system and improve the quality of your sleep.