Below are some of the general subjects that you can pick during your BTech studies, as these course will advance your technical and practical knowledge:
Mathematics: A mathematical background includes understanding of Calculus, Linear Algebra, Differential Equations and Statistic Stamina.
Physics: Mechanics, electricity & magnetism, kinetics & dynamics, thermodynamics and wave & optics.
Chemistry: This common general chemistry course involves sub-topics such as organic chemistry, inorganic chemistry among others.
Programming: C+, Python, Java
Engineering fundamentals: Statistics, dynamics, fluids and their action, heat and its work, properties of matter
Engineering design: Aesthetics, reasoning process, design tools and methods, using of computer-aided design (CAD).
Rest, the subjects taught in the BTech courses would be specialization-specific, based on your chosen field.