Hello Priyanshu,

Here are some of the best books according to the exam pattern. The pattern for AIMA UGAT exam is as follows-

• English Language 
• Numerical and Data Analysis 
• Reasoning and Intelligence 
• General Knowledge

Reference Books for different sections are as follows:

For English:

• Objective General English by R.S.Aggarwal.
• Objective English for Competitive examinations by Hari mohan prasad and Uma Rani Sinha.

For Numerical and Data Analysis:

• Quantitative Aptitude by R.S.Aggarwal
• Numerical ability and Quantitative by P.K.Mittal
• Magical book on Quicker Maths by M.Tyra

For Reasoning and Intelligence:

• A modern approach to Verbal and Non-Verbal reasoning by R.S.Aggarwal
• A modern approach to logical reasoning by S.Chand

For General Knowledge:

• General knowledge and General awareness by Ravi chopra
• Advanced Objective general knowledge by R.S.Aggarwal
• General knowledge by Manohar Pandey

Hope it helped you

Thank you