Hello

You don't need to worry at all dear.

This is because,
There's correction window facility in SSC CHSL using which you can correct your mistake and choose 12th passed . Application correction facility for SSC CHSL 2022 will open on 11th March and will be available till  15th March 2022 (upto11 pm) on its official website i. e ssc.nic.in (http://ssc.nic.in)

For more checkout
https://competition.careers360.com/articles/ssc-chsl-application-form/amp

To help you further,

Here's a brief of your ssc chsl examination pattern.

Your SSC CHSL examination is conducted in three levels or tiers which are listed below:-

----------------) tier -I  :- it is Computer Based examination and questions are asked from General Intelligence, English Language, , Quantitative Aptitude and General Awareness.

----------------) Tier - II  :- it is a descriptive examination and is conducted in pen and paper mode . You have to write  a letter or an application in 150  -  200 words and also   an  essay in  200  -  250 words  either in Hindi or English.

----------------)  tier - III:- it is a skill or typing test.

You can get detailed examination pattern by visiting the page provided below :-

https://competition.careers360.com/articles/ssc-chsl-exam-pattern

Thank you