TCS employee can do freelancing? Is it against policy?

Frame your question correctly
TCS employee can do freelancing? NO Is it against policy? Yes

You can't do freelancing

Strict nooo

Don’t know

Yes it is as they have already cleared about it stating of strict action will be taken if anyone found moonlighting on the things which one that you have mentioned above...If you are actually interested and capable just go for it but better resign and start working on the same to be on safer side ...