School fee payment

We have shifted our daughter from Atomic Energy central school(CBSE), Hyderabad to Jhonson grammar school, Hyderabad in 2020. We joined her (in IIIrd class) in Jhonson grammar school without TC . Due to Covid lock down, we have not approached the old school for TC and informed over the phone regarding the school shifting of our child. In January, 2021 they have sent a letter stating that our child in attending their online classes and an amount Rs 15,000/-(total fee amount) should be payable. We approached the school principal and informed that our child has not attended any online class and told him the school shifting of our child. He told us that joining in other school without TC is illigal and as the TC is not issued, the child is in his school rolls only. So he told that total amount shall be payable then only he will issue TC. I request you to please clarify the below points: 1. Is joining in other school without TC is illegal? 2. Is tuition fee should be payable without attending any classes? 3. Is TC can be obtained without paying the fee?