Question: How to become a district collector?

Ans:

to become a district collector you have to clear civil services exam.

it is divided into three categories 

1.    CSAT

2.    Mains

3.  Interview

Eligibility Criteria for Civil Services :
you must complete or appearing in final year of  graduation from recognized college or university. 

 your age must be within 21 years to 30 years. 
 
And there is relaxation in UPPER AGE limit for reserved category candidates(3 years for OBC and 5 years for SC/ST candidates).