Hi Ronit!
You have made a good decision in planning to write the NDA exam. As you know, while preparing for defense exams like NDA, CDS, etc. you will face a good number of questions related to antonyms and synonyms in the English question paper. One thing is for sure that your knowledge on antonyms and synonyms will be tested differently in various exams but your method of preparation remains the same i.e you need to improve your English vocabulary to excel in these exams.

Following is the link to a pdf that contains around 500 antonyms and synonym questions which are solved:

https://www.ssbcrack.com/wp-content/uploads/2017/11/500_Synonyms_Antonyms_CDS_NDA-Exams.pdf

If you still have any doubts or queries, please feel free to comment below.

Let me know if this answer was helpful to you and all the best for your future!