My grandchildren live with their father in NJ ( who claims he has custodyof children). My daughter who lives in Florida says he only has residential custody. How do I find out what is in effect? How do I get visitation for them to visit me in Florida, what is the requirement? Where can I get a copy of the custody documentation?

You probably have to get them from your daughter. Since you have no standing in their divorce/custody case, the court is not likely to turn over documents to you.

If you want to file for court mandated visitation you can then subpeona the records.

If you know the father's county, you can contact the clerk of family court (or superior or juvenile court, whichever is used) that handles child custody matters. As the clerk to review the plaintiff and defendant indexes to see if either parent has filed a petition in the court. The index will provide this information. Then, if a petition is located, as for a copy of the entire file.