My son was never given a chance to bring up the child. The maternal grandparents took all charge and we would like to know if we have any rights at all?

How old was your son at the time? How old is the child? What is your location?

Your son obviously never exercised HIS rights. Maybe that would be the route to go. Obviously you have no relationship with the other grandparents or the mother either. That was always an option. How old is the child now?

We need more info here. First any question on law needs to include your general locale as laws vary by area. Second, we need to know whether your son was married to the mother. We need to know if he was listed as the father on the birth certificate. We need to know whether he signed an acknowledgment of paternity. We need to know how old he was when the child was born and how long ago the child was born.

Bottom line here, I'm going to assume he was not married to the mother. If that is the case, then he needs to file for paternity, custody and/or visitation with a local Family Court.

You have very limited rights, if any. And none until he is acknowledged as the legal father.

As note above you gave us very little to go on. Is your son still alive and well? I ask because when you refer to his relationship with the child/or lack there of it is in the past tense. All other questions are all valid and necessary to give you an accurate answer. Some places (like my home state) you will have more rights than others but it is all dependent (even where grandparent rights exist) upon things already asked.