You have asked a rather unusual question, but I will attempt to provide some insights that may be helpful to you. First and foremost, you need to determine the nature and size of the industry in which you wish to focus your research. Once you have made this decision, you can select some HR-related topics such as HR practices, HR policies, promotional policies, manpower composition, welfare measures, CSR policy and operations, industrial relations machinery and its operations, grievance redressal machinery and its operations, and so on. It is then up to you to decide which specific area you want to concentrate on based on your interests. Some individuals are keen on becoming experts in establishment/administrative matters, while others focus on welfare measures or industrial relations/legal matters, and so forth. Ultimately, the choice of field and the nature and size of the industry you are interested in are yours to make.
Regards,
AK Jain