Best practice books for mechanical engineering for the gate, CSE and ESE

Graduate Aptitude Test in Engineering (GATE) is basically a national examination on the comprehensive understanding of the candidates in various undergraduate subjects in Engineering / Technology / Architecture and post-graduate level subjects in Arts, Commerce and Science.
The GATE score would reflect the relative performance level of the candidate in a particular subject, which is quantified based on several years of examination data.
It is conducted jointly by the Indian Institute of Science (IISc), Bangalore and the seven Indian Institutes of Technology (at Bombay, Delhi, Guwahati, Kanpur, Kharagpur, Madras and Roorkee) on behalf of the National Coordination Board (NCB)-GATE, Department of Higher Education, Ministry of Education (MoE), Government of India.
Qualifying in GATE is a mandatory requirement for seeking admission and/or financial assistance to: (i) Master’s programs and direct Doctoral programs in Engineering/Technology/Architecture and (ii) Doctoral programs in relevant branches of Arts and Science, in the institutions supported by the MoE and other Government agencies. Even in some colleges and institutions, which admit students without MoE scholarship/assistantship, the GATE qualification is mandatory. Further, many Public Sector Undertakings (PSUs) have been using the GATE score in their recruitment process.