NIOS self-instructional materials (SIMs) - These are the most important resources as they're specifically designed for the curriculum

NIOS sample question papers and previous years' papers

NIOS study guides available on the official website

NCERT textbooks for respective subjects (these align well with NIOS curriculum)

Subject-specific guides from publishers like S. Chand, R.S. Aggarwal (especially for Mathematics)

NIOS's official YouTube channel NIOS Virtual Open School

SWAYAM portal's NIOS courses

NIOS Mukt Vidya Vani (audio programs)

NIOS Physics self-instructional material (covers all modules)

HC Verma's Concepts of Physics (excellent for concept building)

DC Pandey's Understanding Physics series

SS Krotov for problem-solving practice

NIOS Chemistry self-instructional material

Morrison and Boyd for Organic Chemistry

P. Bahadur for Physical Chemistry

Pradeep's Chemistry guide

RC Mukherjee for Chemical Calculations

NIOS Mathematics self-instructional material

RD Sharma's Mathematics for Class 12

ML Aggarwal Mathematics

SL Loney for Trigonometry

Arihant's Mathematics Problem Solver

NIOS English self-instructional material

Wren & Martin's English Grammar

Word Power Made Easy by Norman Lewis

Golden Guide for English Literature

BBC Learning English website for language skills

Solve previous 5 years' NIOS question papers

Use NIOS study apps

Watch video lectures on NIOS Virtual Open School

Join NIOS live sessions on Mukta Vidya Vani

Mechanics

Electromagnetism

Modern Physics

Optics

Organic Chemistry reactions

Chemical Equilibrium

Electrochemistry

Chemical Kinetics

Calculus

Algebra

Coordinate Geometry

Vectors and 3D Geometry

Writing skills

Reading comprehension

Grammar fundamentals

Literature texts