The mass region 170 - 190 is basically a transitional region between the strongly deformed rare earth nuclei and the spherical lead isotopes. The nuclei, belonging to this region exhibit softness in their nuclear potential and therefore are better known as 'gamma-soft nuclei'. For these nuclei the proton Fermi level is in the vicinity of highly down sloping low K, high-j orbitals like proton h_9/2[541]1/2^- and proton i_13/2[660]1/2^+, intruding from above the Z = 82 shell closure. Depending upon the type of orbital occupied by the odd particle, these nuclei are expected to exhibit a variety of nuclear shapes. So, this mass region is rich in nuclear structural properties and therefore offers a wide possibility for the nuclear shapes studies. In the present work, an attempt has been made to study the structural properties of nuclei of this mass region at high spins through level lifetime measurements.