my humble opinion:
This is a list for design beams reinforced ,
3T16-6-200-B1
3 --> numbers of reinbar
T --> Steel material code , Like HRB400 , RRB500, ect.
16 --> reinbar diameter , mm
6 --> sectional area of 3T16 , 6cm*cm
200--> beam width , mm
B1 --> Reinforcement scheme code .