Hello Aspirant,

If you have completed the application clicking final submit and paid the fee , then it is not possible to correct the form.Only in the registration process you are allowed to modify the details twice. But apart from mistakes in photo or signature uploads , mistakes regarding qualification can be corrected during document verification. It won't be that serious a problem. The science group option is asked only to make you eligible for data entry position , so if you are not opting for data entry post then it will not matter. So do not worry much , keep visiting the website for future notifications as sometimes they make give small window of time for application correction ,during which you easily change the details. Focus on preparation now and kindly refrain from making a new second registration just to correct this  mistake as it will put you in trouble once the authorities find it out .

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

All the best