Is professional fees clause applicable on teaching in school

A person teaching biology can be regarded as technically qualified in the subject and even though specifically not mentioned in the list of professional u/s. 44AA(1), but can earn professional fees. Here you are appointed on contract basis and not as employee, that itself authenticates it, when you accept the terms.

Well, there is no loss even after TDS deduction, which you can claim back by filing return; but I see it as better option.

The professional income is assessed under head 'PGBP' and not 'Salary'.

TDS u/s. 194J woulds be deducted at 10% of the payment received. Quarterly statement of TDS deduction will be issued by the deductor.

You can declare the income u/s. 44ADA. and offer min. 50% of the receipts as taxable. E.g. 22000 *12 *0.5 = Rs. 1,32,000/- No need to maintain books of accounts. If Total/ aggregate income is below 2.50 lakhs after all other deduction like 80C, 80D, 80TTA etc., you can claim total amount of tax deducted as refund!!