TISS - Tata Institute of Social Sciences Mumbai Answered Questions

Candidates should have completed B.A. Psychology, or B.A. General, with minimum three papers in Psychology. B) Candidates who will appear for their final year B.A. Examination in 2019, with the above subjects and are awaiting results are also eligible to apply. CAT the time of applying candidates studying in 3 year degree programme should have passed in all the subjects for the 1st to 4th semesters and candidates studying in 4 year degree programmes should have passed in all the subjects for 1st to 6th semester. D) Only those Candidates who will be able to complete all the requirements of their final year Bachelor's Degree examinations by June 08, 2019 are eligible to apply to all the programme.

For vocabulary, you can refer word power, its one of the good books. It is preferred for MBA and GRE preparation too.
For reading comprehension, you can refer books from Arihant Publications, comprehension.
Proficiency in Reading Comprehension simplifying the Passage for you: Ajay Singh.
For Quantitative, Logical Reasoning and Data Interpretation or Sufficiency RS Aggrawal and arihant publication are best
Verbal and Non-Verbal Reasoning- R S Agrawal
Data Interpretation and Data Sufficiency Arihant
If you have books for CAT preparation, you can refer those books.

No, there is no such difference between MBA in HRM and PGDM in HR. It is the naming convention which has to be followed. If any institution is not having university status, then it can only give out Diplomas and not degrees and MBA is a degree and PGDM is a Diploma, which is equivalent to MBA by Indian Association of Universities. So, earlier IIMs were giving out PGDMs, but now they have shifted to MBA after cabinet has claw Fred the bill.