I would think that any court would think it would be in the bedt interest of the kids to continue the relationship between myself and the kids, especially when I can clearly show a strong bond since birth and the only stability they have had. She is in jail now and kids are with a guy they barely know. How is that situation better for them? They have never been left with anyone but me before.
You really need to seek advice from family law attorneys in both states. It may be that the kids would be better off with you, but that is not all there is to it. As I explained before, if the action is brought in Indiana the law limits the circumstances in which you can bring an action for visitation in the first place and it sounds like your situation won’t fit any one of those three sitautions. If you don’t fit the situations that the law says you must have to file the visitation petition you lose even if it is clear the kids would be better off with you. The problem with suing in Kentucky is that the kids right now do not reside in Kentucky and Kentucky law says you must file in the county where the kids reside. If they do not reside in Kentucky then it would seem you cannot file in that state. You need to see attorneys in both states to see if there is some way around those problems in each state.
And even once you are able to file the petition, there is still the problem that the parents have constitutional rights that the courts cannot ignore. In general, the Constitution gives fit parents the right to determine with whom their children visit. By the way, visitation is not the same as custody. It sounds like what you really want is custody of the kids (i.e. to have your home as their primary residence and you as their primary caretaker), not just visitation once in a while with them. Assuming the parents are fit, they get custody of their kids, even if the grandparents might be better caretakers for the kids. The parents have that right to custody of their kids unless they have been determined unfit and their rights terminated.
Your son probably ought to file for divorce and seek custody of the kids. If he succeeds in that, then he can allow you to see the kids on his time.
I realize that it is frustrating to see the grandkids have to deal with the kind of situation they are in and I understand why you want to help the kids. But understand that it is not as easy or straightforward for you to get even visitation here as you seem to think. Talk to the family law attorneys in both states and they'll explain to you the challenges involved.