It is good that you have qualified in NET as that paves a way for you to apply for the post of lecturer ship in the colleges and universities. Anyway, now you are aspiring for doing PhD in commerce field. So, you have to select a good topic for PhD and apply for admission in some good institution to fulfil this objective.
I understand that there are many subjects and topics where there is ample scope of research and studies in this arena of commerce which is very much connected with the financial and commercial world and you would be discussing it with your guide or mentor when you would be joining a suitable college or university to pursue this aim in your life. Just for a reference, there are many sub categories in commerce area where one can focus for searching good topics for PhD. Some of these niche areas are Public Administration, Accounting, Project Management, Innovation and entrepreneurship, Marketing and branding, Financial areas, Management and leadership issues, Business management and administration etc.
There are many institutions that offer for PhD and you can choose out of them as per your choice. Some of the good institutions especially in the Northern India region are as follows -
1. Delhi University, New Delhi.
2. Amity University, Noida, UP.
3. NIMS University, Jaipur, Rajasthan.
4. Goswami Ganesh Dutt Sanatan Dharama College, Chandigarh.
5. Sharda University, School of Business Studies, Greater Noida, UP.
6. University of Rajasthan, Jaipur, Rajasthan.
7. University of Lucknow, Lucknow, UP.
8. Chaudhary Charan Singh University, Meerut, UP.
Knowledge is power.