Yes, there is relaxation in the age limit for candidates belonging to the SC/ST category in the BPSC (Bihar Public Service Commission) exam. The relaxation is provided to ensure equal opportunities for candidates from these communities. The details of the relaxation in age limit for SC/ST candidates are as follows:

1. Age Limit:
Candidates belonging to the SC/ST category are granted relaxation in the upper age limit as per the guidelines of the Bihar government. The relaxation in age limit can vary depending on the specific recruitment notification issued by BPSC. Generally, the relaxation is provided as per the following norms:

- The minimum age limit for SC/ST candidates remains the same as the general category candidates.
- The upper age limit for SC/ST candidates is extended by a certain number of years, typically ranging from 3 to 5 years, depending on the specific recruitment notification.
- The exact age relaxation for SC/ST candidates can be found in the official notification of the BPSC exam.

2. Proof of Category:
To avail the age relaxation, SC/ST candidates need to produce valid documentary proof of their category. This can include caste certificates issued by the competent authority, such as the District Magistrate or Sub-Divisional Officer.

3. Reservation:
In addition to the relaxation in age limit, SC/ST candidates are also eligible for reservation benefits in the BPSC exam. The reservation quota for SC/ST candidates is fixed as per the guidelines of the Bihar government. This ensures that a certain percentage of vacancies are reserved for candidates belonging to the SC/ST category.

4. Other Eligibility Criteria:
Apart from the age relaxation, SC/ST candidates need to fulfill the other eligibility criteria set by the BPSC. This includes educational qualifications, experience (if required), and other criteria specified in the recruitment notification.

In conclusion, there is a relaxation in the age limit for candidates belonging to the SC/ST category in the BPSC exam. The specific relaxation in age limit can vary depending on the recruitment notification, and SC/ST candidates need to produce valid documentary proof of their category to avail the benefits.