Is doing B.Com from IGNOU a good idea?

It's not a bad idea if you are thoughtful enough to do this course without being admitted to a regular university. 

If you rely entirely on the staff and have blind faith that they will assist you with all of your questions, you may have difficulty sorting it all out on your own. It's a university where you have to apply and do everything on your own. This is what distinguishes and challenges IGNOU.

If you decide to apply for B.Com at IGNOU, read the prospectus carefully and keep it with you. The prospectus will provide you with all of the information you require.