Hi Anandv,

The most important chapters for NDA & IISC are:-

• Permutation & Combination
• Trigonometry
• Straight Lines and Conic Sections
• Complex numbers
• Matrices and Determinants
• Vectors and 3D Geometry
• Differentiation and Integration

NOTE: These important topics are listed on the basis of previous year Exams, in rare cases, some topics may vary.

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!