Master in Business Administration (MBA) is two years degree course in the field of management. In India MBA degree can be awarded by any recognised university or by a Business School affiliated to any university. Post Graduate Diploma in Management (PGDM) is a two years diploma course offered by the institutes that are recognised by the All India Council for Technical Education (AICTE) and which are autonomous and not affiliated to any university. It is not mandatory that a PGDM is equal to MBA. PGDM institutes accreditation by Association of Indian Universities (AIU) makes an institute's PGDM course equivalent to an MBA.
There are a large number of similarities between the curriculum of both MBA and PGDM. An MBA institute follows a fixed curriculum as it will be based on the university guidelines which occasionally may not be aligned to industry requirements. Autonomous institutes do not follow university standards, so it is have the flexibility to align its curriculum according to industry standards and change in the business environment. Some of the PGDM from IIMs, XLRI etc has more value then MBA. However MBA of FMS DU, IIFT etc have similar value as IIMs. Students are advised to chose Institute based on its ranking not on nomenclature of degree.
Refer
https://www.shiksha.com/mba/ranking/top-mba-colleges-in-india/2-2-0-0-0 for ranking of BSchools and their degree management courses.
Executive MBA is an intensive one-year residential or distance learning or combination of residential & distance learning programme created specifically for professionals with 5 years or more work experience. Executive MBA provides students with the same solid foundation in key management concepts and disciplines as a two-year fulltime MBA. Executive MBA course work is build on the basis of that students will have diverse and extensive work experience by virtue of which they will able to related to management theories and concepts. Executive MBA is rigorous as syllabus of two year is compressed in one year.