Two-Dimensional (2D) topological insulators (TIs), are new and promising materials for the applications such as spintronics and optoelectronics due to their unique surface states that are topologically protected and thus robust against nonmagnetic impurities and disorders. The existence of these remarkable electronic states in TIs can be attributed to the large spin-orbit (SO) coupling. The researchers have paid attention to Bi based two-dimensional materials due to high SO coupling effect. Among them, GaBi, InBi, GaBi3 and InBi3 are good candidates for 2D Tls materials. Although there are a lot of studies in these 2D Tls, a detailed understanding of the effect of E-Field is lacking. Applying external E-field can change the electronic properties, which may enable to realize the change on the properties of the materials. We have performed theoretical study of GaBi, InBi, GaBi3 and InBi3 to investigate the effect of E-field to explore band structure, charge distribution and geometries.