Technically one's age has to be larger than 0 for one to be considered to be existing.
(Therefore I don't consider this question as ambiguous.)
But you don't really have to care if it is age in years or in days.
From this we know:
We want to know if R-T>0.
The answer depends on whether T is greater than 6 years old. So if T is now 4 years old, for example, then we know that R is littler (2year old). If T is 7 years old now, then we know that R is older (8 year old). It really doesn't matter whether it is 4 years from now or not. However, III could be right or wrong from the beginning.
Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.