Can we apply for ILR?? Please Help!

Hi, hope I’m in the right place, desperately seeking advice on my husbands application. In 2014 he was granted 2.5 years discretionary leave to remain (after our appeal was accepted in the tribunal) we applied in 2016 for an extension of the DL and was granted a further 2.5 years based on family/private life (not discretionary leave this time). My question is neither of his limited leave letters state which route he is on (2 year, 5 year, 10 year) so we are not sure if we have to apply for another 2.5 year extension or if we can apply for ILR seeing as he has had limited leave for 5 years now.
Any help would be greatly appreciated
Thanks in advance

Both DLR and FLR(FP) are 10 year routes

Thank you for your reply. I was confused as others I’ve seen state 5 or 10 years on their letters but ours didn’t.
Thanks again