Many Class 10 and 12 students want extra help before board exams, and many parents prefer small live batches to large coaching centres. You can teach from home with a laptop, a steady internet connection, a good microphone and a writing tablet or whiteboard.
Pick one or two subjects you know well, run a free demo class to fill your first batch, and keep batches small so every student gets attention. Udyam registration is optional but useful once you start invoicing. Fees and demand depend on your city, board and subject, so check what local tutors charge first.