Hi Sharmishtha!

As per the eligibility criteria to write UPSC , candidate's minimum age should be 21 years on/before1st August of the year (exam writing year). So, as you are born on 23rd May 2021 and you will turn 21 on 23rd May , 2025. So, yes you are eligible to write UPSC 2025 exam. And you can write the exam upto 6 attempts (general category).

To know more, visit here:

UPSC IAS Eligibility Criteria 2022 - Age, Qualification, Nationality, Medical Standards (careers360.com)

Thankyou!