Hello Bhawna

For the preparation of Any entrance exam you must prepare well before with their sample papers and previous year's papers. 

Some of the important topics which will be part of NIFT syllabus 2019 and from where questions will be asked in General Ability Test (GAT) are: 

Quantitative ability

English Comprehension 

General Knowledge and current affairs

For the each and every details and previous year's question you can follow this link : https://design.careers360.com/articles/nift-question-paper