"资格要求严的" can be translated into English as "with strict qualification requirements" or "having rigorous qualification criteria".
Here are a few example sentences to illustrate the usage:
1、 This position is with strict qualification requirements, so only a few candidates are eligible.
(这个职位资格要求严,所以只有少数候选人符合条件。)
2、 The organization has rigorous qualification criteria for its members.
(该组织对其成员有严格的资格要求。)