As per your request I am here suggest you books for Union Public Service Commission (UPSC) - Indian Engineering Service (IES) exam.

UPSC IES Books:

Indian Geography
By TTK (New Modern School) or Oxford

World Geography
By Gohcheng- Leong

Constitution of India
By Subhash Kashyap

For Current Affairs
GENERAL STUDIES by ENGINEERS INSTITUTE OF INDIA

Strength of Materials /Mechanics of Structure
By Gare & Timoshenko, E.Popove, L. Singer, B.C. Punamia

Fluid Mechanics and Fluid Machines
By Modi & Seth, R. K. Bansal, A.K.Jain K.Subramanyam, Jagdish Lal.

Signal and System
By Oppenheim and Willsky

Power Electronics
By PS Bhimra

Monochrome and colour
By R.R. Gulati

Compressible Flow
By S.M. Yahya John D. Anderson

Heat and Mass Transfer
By P. K Nag, JP Hollman, D.S. Kumar,
R.C. Sachdeva

Operations Research
By A.M. Natarajan, P.Balasubramani

Strength of Materials
By Timoshenko gere, RAMAMRUTHAM, B.C. Punamia