If current ''I''(say 3A) enter through two parallel resistor r1,r2(6ohm,3ohm) then expression for current through either resistor, also solve for 3A ,6ohm,3ohm

for the 6 ohm resistor  the resistanc is high hence  current will be low  

ths means current will be 3/6+3  times the input current  similarly for the  3 ohm  current will be 6/6+3    times the  input current  for 3amp

6 ohm ----- 1amp

3 ohm----- 2 amp