Both of the books are beneficial for you to study. However NCERT books are off extra help. You can prefer NCERT books for preparation of NMIMS. I am mentioning below the name of the books which will also be fruitful and useful for you other than NCERT books:

• Quantitative aptitude by S Chand and Dr RS Agrawal
• Inspiring strategic preparation by Edugorilla
• Super 20 sample papers combined book for all subjects
• Lucent general knowledge

Read more about NMIMS preparation by clicking on mentioned below link:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/university/narsee-monjee-institute-of-management-studies-mumbai/amp&ved=2ahUKEwjr29jJiZz1AhUy7XMBHQG_DugQFnoECAoQAQ&usg=AOvVaw3TMthyZW6NoETph8jDuqf6