Sir,
Collection of tax at source (TCS) under Section 52 of CGST Act, 2017 is in respect of electronic commerce operator. TNEB is not electronic commerce operator. Hence Section 52 is not applicable to them.
Tax deduction at source is, as per Section 51 (1) of CGST Act, 2017, in respect of
(a) a department or establishment of the Central Government or State Government; or
(b) local authority; or
(c) Governmental agencies; or
(d) such persons or category of persons as may be notified by the Government on the recommendations of the Council,
(hereafter in this section referred to as “the deductor”), to deduct tax at the rate of one per cent. from the payment made or credited to the supplier (hereafter in this section referred to as “the deductee”) of taxable goods or services or both, where the total value of such supply, under a contract, exceeds two lakh and fifty thousand rupees:
In your case you are not supplying anyh goods/services to TNEB. If you do so then when macking payment to you TNEB has to deduct tax at source at the prescribed rate.
Moreover according to sl. No. 25 of Notification No. 12/2017-C.T (Rate) dated 28.06.2017 as amended transmission or distribution of electricity by an electricity transmission or distribution utility is chargeable to tax At 'Nil' rate.
Therefore you are advised to take up the matter with TNEB.