Generally, people pursue PHDs because they have an idea/ideas that they wish to expand on, with the general aim of contributing to the development of an academic field.
Clearly, Kishore has no idea. Perhaps he is not suited for a PHD. Afterall, to be ready for a PHD program comes at a particular level of intellectual maturity. Perhaps Kishore is just not ready, if he is going on an ESSAYFORUM website, and asking people for topics in marketing even though he should have a clear idea as to what topics it is in marketing that he is interested in and willing to research.