I qualify gate 2020 in general category .can i take admission in ccmt 2021 under ews category.
As mentioned in the FAQ's by CCMT here
It is not possible.
Please make sure you fill in the category properly as you will be liable to produce the correct certificate, failing which you will be considered under the general category.
Any additional CCMT related information is available here https://engineering.careers360.com/articles/ccmt
I hope this information helps.