Hey I have managed to do it

Basically you need to do 3 steps

In your Android , appart of termux you need to have installed Termux API
Then in termux itself
pkg install termux-api
Then on your $HOME/.tmux.conf add the following directive
if-shell '[ -n "${TERMUX_VERSION}" ]' 'set -g @override_copy_command "termux-clipboard-set"'

Now upon doing Copy-mode , select the buffer , press y . It should work