I am working as a secretary to a director. I want pursue an MBA without leaving my job. Which Mumbai universities are AICTE approved?

It's good to read that you want to pursue MBA. Since you are employed I would suggest you to explore executive MBA. It's of a shorter duration and also curriculum is more relevant. Most colleges in Mumbai that offer full time MBA also offer an Executive MBA programme. Pick a college keeping in mind

Hello sir, greetings! One way to make sure you don't lose your job is- You can study with the reference of the company, you just have to assure them that after MBA, you are going to work in their company. They will help you in completing your MBA and your job will be saved too. Good luck.