The value of equivalent resistance between the points A and B in the given circuit will be:

Resistances shown on the right side are connected in parallel to each other, hence can be shown as:

R and 3R are connected in parallel, hence can be written as:

$\frac{1}{R_p}=\frac{\text{1}}{\text{R}}+\frac{\text{1}}{\text{3R}}$

$\frac{\text{1}}{{\text{R}}_{\text{P}}}=\frac{4}{\text{3R}}\Rightarrow {\text{R}}_{\text{P}}=\frac{\text{3R}}{4}$

The remaining two resistances, R are connected in series.

${\text{R}}_{\text{S}}=\text{R}+\frac{\text{3R}}{4}+\text{R}=\frac{\text{4R}+3\text{R+4R}}{4}=\frac{\text{11R}}{4}$