There are relaxations in the age limit for candidates from reserved categories in the NABARD Grade B Exam. The age limit criteria for the exam vary for different categories such as SC/ST, OBC, PwD, and Ex-servicemen.

Age Relaxation for SC/ST Candidates:
- The maximum age limit for SC/ST candidates is relaxed by 5 years.
- So, the upper age limit for SC/ST candidates is 35 years.

Age Relaxation for OBC Candidates:
- The maximum age limit for OBC candidates is relaxed by 3 years.
- So, the upper age limit for OBC candidates is 33 years.

Age Relaxation for PwD Candidates:
- The maximum age limit for PwD (Persons with Disabilities) candidates is relaxed by 10 years.
- For PwD SC/ST candidates, the age limit is relaxed by 15 years.
- For PwD OBC candidates, the age limit is relaxed by 13 years.

Age Relaxation for Ex-servicemen Candidates:
- The maximum age limit for Ex-servicemen candidates is relaxed as per the government rules.
- The relaxation is based on the length of military service provided by the candidate.
- The upper age limit for Ex-servicemen candidates can vary depending on their category and the number of years of service.

It is important to note that candidates claiming age relaxation under any reserved category must provide valid and authentic documents to support their claim. These documents may include caste certificates, disability certificates, or any other relevant certificates as per the category.

Summary:
- SC/ST candidates have a relaxation of 5 years in the upper age limit.
- OBC candidates have a relaxation of 3 years in the upper age limit.
- PwD candidates have a relaxation of 10 years, with additional relaxation for PwD SC/ST and PwD OBC candidates.
- Ex-servicemen candidates have age relaxation as per government rules based on their length of military service.