Hi, you can refer these books to prepare for SSC GD Constable exam:
General Intelligence and Test of Reasoning - Vikash Publishing House
A Modern Approach to Verbal & Non-Verbal Reasoning - R.S Aggrawal
General Knowledge 2018 - Manohar Pandey
Objective General English - S.P Bakshi
For further details, you can read the following article: https://competition.careers360.com/articles/ssc-gd-constable-syllabus
Best of Luck
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