S. 201 : Deduction at source-Failure to deduct or pay-Leave travel concession-Estimate of income-Assessee in default Public sector Bank-Employees travelling not only to domestic destination but to foreign countries-Not taking shortest possible route-Employees not entitled to exemption-Leave travel concession reimbursed without deduction of tax at source-Assessee could not claim ignorance about travel plans of employees-Complete facts available-Not a bona fide mistake-Liable to pay interest. [S. 10(5), 192(1), 201(1), ITR. 2B]