You can watch the lecture series on BYJU’S Exam Prep app and youtube and can also follow 60 days study plan for DFCCIL to save time and understand more concepts in lesser time. But if you still want to follow books,you can refer to these books
A Modern approach Verbal and Non-Verbal Reasoning: BS Sijwali
Dedicated Freight Corridor Corporation India Ltd-Dfccil-Junior Manager : Dr. Chandresh Agarwal
Quantitative Aptitude For Competitive Examination: The Pearson Guide