Legal Question in Family Law in Indiana

Under Indiana Law, does rings, not neccessarliy for engagement and other gifts such as a watch and a neclace have to be retuned in a non marital relationship?

No (assuming you mean returned 'If the relationship ends", though you didn't ask that.

Under Indiana law, in a non marital relationship, if there were talk of a marriage, does an engagement exist?

No, talk doesn't do anything. Asking and acceptance does.

In this subject are any of the parties entitled to anything?

Don't understand what you are asking about.

If a gift was given and marriage had nothing to do with the gift, in other words not an engagement ring, and the gift was unconditional, the recipient may keep the ring.

Talk of marriage and engagement are two different things.