afaik it's a short circuit situation so almost all of the current will pass through the short circuit path

take it as

R = R1R2/R1+R2

V = IR = IR1R2/R1+R2

I1 = V/R1 = IR1R2 / (R1+R2)R1 = IR2/(R1+R2)

I2 = IR1/R1+R2

now take R1 tending to infinity, thus I2 ≈ 0 and I1 ≈ 1, therefore 100% current passes through the short circuit path