Every class has a stat maximum that they can reach, once they reach the maximum they can only proceed if they Rank Up. The stat Maximums are:
Genin
Health Points: 1000
Chakra Points: 500
Attack Points: 100
Defence Points: 100
Life Points: 200
Stamina Points: 100
Counter Points: 100
Ninjutsu Point: 200
Taijutsu Points: 200
Genjutsu Points: 200
Seal Points: 200
Chunin
Health Points: 2000
Chakra Points: 1500
Attack Points: 200
Defence Points: 200
Life Points: 400
Stamina Points: 200
Counter Points: 200
Ninjutsu Point: 400
Taijutsu Points: 400
Genjutsu Points: 400
Seal Points: 400
Jounin
Health Points: 3000
Chakra Points: 2500
Attack Points: 300
Defence Points: 300
Life Points: 600
Stamina Points: 300
Counter Points: 300
Ninjutsu Point: 600
Taijutsu Points: 600
Genjutsu Points: 600
Seal Points: 600
ANBU
Health Points: 4000
Chakra Points: 3500
Attack Points: 400
Defence Points: 400
Life Points: 800
Stamina Points: 400
Counter Points: 400
Ninjutsu Point: 800
Taijutsu Points: 800
Genjutsu Points: 800
Seal Points: 800
Kage
Health Points: 5000
Chakra Points: 4500
Attack Points: 500
Defence Points: 500
Life Points: 1000
Stamina Points: 500
Counter Points: 500
Ninjutsu Point: 1000
Taijutsu Points: 1000
Genjutsu Points: 1000
Seal Points: 1000