Hi Riyashahid! There is no specific best book for the judiciary exam. But there are books given as follows which you can go through for entrance examinations:

Study Package for Clat and LLb by A P Bhardwaj

Universal's Guide to CLAT & LL.B. Entrance Examination2018-2019

Compulsory English for Civil and Judicial Services

I hope this information has helped you:)