I have a BE in Electronics and Communication and my work experience in the last decade has been in the field of Electronics. I have always nurtured a strong interest in Philosophy and have written a lot in the field (blog posts, plays, a book). Do I have a fair chance at being selected for a PhD program or would I need to do a masters first? The profiles of existing students in most of the good universities seem to outmatch mine by miles and so this is more a question on my chances rather than one on technical requirements for the application process.
Best way is to approach the institutions/departments you are interested in considering for application, and ask for their specific requirements, which should be very clearly stated.
They will know better than anyone else. Different departments are likely to have different requirements.
That does not meant your set of circumstances will satisfy any of them.