Is it possible to do PhD in pure mathematics after engineering I have an MTech in Industrial Drives and Control (Electrical Eng). After that could not go for any work... After giving some tuition, I came to the conclusion that I am genuinely interested in mathematics... be it to study or to teach. Is it possible for me to do a PhD in mathematics? Or, are there any PhD options in Electrical Eng that are related to mathematics? I am even ready to take time and get a bachelors and masters in mathematics by distance education.
Sure, it is "possible".  

I really question your stated rationale for it, though (couldn't get a job in engineering, thus staying in school and moving to a field that usually has harder time with job placement).  I think you would be better served beating the bushes and getting a job.