Hi Aspirant

If you are not willing to quit your job then there are two options:

1.Distance learning (Where you join some distance learning programs offered by university/colleges)

2.Online certification courses  (There are several online platforms which provides you the courses which will benefit you)

It depends on you which one you choose.

Some of the best Distance MBA colleges in India are:

• NMIMS Global Access School for Continuing Education 
• Symbiosis Centre for Distance Learning (SCDL)
• IMT-Centre for Distance Learning (IMT-CDL) Ghaziabad
• Indira Gandhi National Open University (IGNOU)
• Sikkim Manipal University- Distance Education
• Jaro Education (online course )
• Coursera (online course)
• edx.org (online course)

All the best