Can I play high end games on my rooted low end phone
To the best of my knowledge, just having your phone rooted does not make it Memory efficient  and that means it will not automatically become suitable for high end mobile games.

Rooting phone gives you additional privileges, one of most common of which is a privilege to remove system apps that are shipped by your device manufacturer.

You can try this yourself, by downloading some bulky apps from Play store and soon when you will reach device memory threshold, you will find that Android OS will complain and ask you to free some memory, albeit your phone is Rooted.

Good Luck!!