Both IGNOU and Sikkim Manipal University are good options for MBA. But considering the fact that you are a working professional, you need to keep some points in mind regarding both universities.
IGNOU-
Less fees structure as compared to Manipal University
Extensive study material
Haa branches worldwide
A large number of regional centres
Has a lot of value is the best open university in the world.
Does not facilitate online fee submission
Does not provide placements
Sikkim Manipal University-
It offers an app from which you can download your textbooks, assignments, and materials
Doubts can be cleared online from a registered student account.
They will give you up-to-date notifications regarding exams, imp dates, materials, and placements via mail
Any queries will be handled by the Sikkim University team quickly and professionally.
Online payment of fees is available
Offers placements for those who have completed their graduation.
All exams are online (theory and objective both)
Less descriptive study material
You can see the pros of Sikkim Manipal University are more than those of IGNOU. Being a working professional, Sikkim University offers you better features than IGNOU.