• Strength of MaterialDr. R. K. Bansal2
• Strength of MaterialU. C. Jindal
• Strength of MaterialB. C. Punmia
• Structural Analysis  Theory of structuresS. Ramamrutham & R. Narayan
• R.C.C. Design  Reinforced Concrete DesignDevdas Menon & S. Pillai
• Design of Steel StructureS.K. Duggal
• Environment Engineering Water Supply Engineering:

• Sewage Disposal and Air Pollution EngineeringS. K. Garg
• Soil Mechanics Basics and Applied Soil MechanicsGopal Ranjan & A. S. R. Rao
• Hydraulics and Fluid MechanicsDr. P. N. Modi & Dr. S. M Seth
• Fluid Mechanics in SI UnitsYunus Cengel
• Highway EngineeringS. K. Khanna & C. E. G. Justo12Surveying (vol. 1,2,3)B. C. Punia, Ashok Jain & Arun Jain
• Engineering HydrologyK Subramanya
• Irrigation Engineering and Hydraulic StructuresS. K. Garg
• Construction Material & ManagementS.C Rangwala, M.L. Gambhir, B. C. Punia

Hello Jogesh!

Preparing from Gate with the help of book only is not an easy task. You can take help of books but you should prepare self handwritten notes or get from any coaching.You can use books when the topic is not clear from notes.

Some suggested books are:

Engineering Mathematics:HK Das

Fluid Mechanics by RK Bansal

Environmental Engineering by Garg

Structural Analysis:Ramamurtham

You should also go through the previous year question papers so that you can get the idea which types of questions comes in the exam.

Hope it answer your concerns.