I am a passout student from mechanical.in 2016 and having 4 years gap.is that right time to start study again for GATE exam and ese exam

Hello,
Since there is no age limit for GATE you can appear in the exam at any age.But for ESE the maximum age limit is 30 years and relaxation is given for reserved category.So age criteria is not a hindrance to appear in GATE and ESE.Ans yes, you can prepare for both if you are interested to pursue higher studies or get in PSUs or Engineering services.And you might face questions about the gap in your career at the time of interview, justify the gap honestly.You will not face any problem.