Hinduism meanse way of life. Which contains very diverse defination of religion. It is very much open.
"Do your karma without expecting reward of it, reward will automatically come to you. Do good deed you will get good reward for bad you will get bad reward."
This is the defination of hinduism.
Hinduism was found by Lord brahma (ME people tells him Abraham). Who created humanity. By that meanse hinduism is more than millions of year old relgion.
Correct defination of hinduism comes in picture before 7000 Yrs when we found our language sanskrit.