can this sort of relation be considered for marriage?

Hi ivlakshmi,
If you are OK with your mothers opinion, don't worry. This too shall pass. Think of it that it didn't reach them and fall out which would have been even more worse.
But if you feel you want to go ahead and don't mind the age or the relation thing then speak to your mother honestly to give it a try only after making sure the character if the guy. Again have no expectations.
Either way think about it.
It will work out if it was meant to be.
Take care,
Cliona