The Syllabus for Physics Includes:

Physical World and Measurement

Kinematics

Laws of Motion

Work, Energy and Power

Motion of System of Particles and Rigid body

Gravitation

Properties of Bulk Matter

Thermodynamics

Behaviour of perfect gas and kinetic theory

Oscillation of waves

Electrostatics

Current Electricity

Magnetic effects of current and magnetism

Electromagnetic induction and alternating currents

Electromagnetic waves

Optics

Dual Nature of matter and radiation

Atoms and nuclei

Electronic devices

So Communication System is not a part of NEET Syllabus. You can also check the official Information Bulletin Page no: 42 : https://ntaneet.nic.in/ntaneet/ShowPdf.aspx?