I would like to know if the mother and father has abandon their child for 3 years to the grandmother ,what are te charges and future of the child custody
?

I would like to know if the mother and father has abandon their child for 3 years to the grandmother ,what are te charges and future of the child custody
?
If grandmother can prove child was well cared for during this long time in a child's life, what charges ?

Don't really know know what you are asking?

You have to explain what the issues are.

Child Abandonment is a criminal charge that means a child was left without any adult supervision. That doesn't seem to be the case here as you indicate the grandmother has been caring for the child. In a very few states, it can also mean non payment of court ordered child support. But, again, that doesn't seem to apply here.

Has ANY court action been taken? Was the grandmother awarded guardianship or custody by court order or the parents signing a document bestowing temporary guardianship?

You need to give us some more background here, including the area involved as laws vary by area.