Is WhatsApp an eligible medium for sending a notice to a tenant?

I have notified my tenant of the rent increase 90 days in advance of the expiry date of the tenancy contract via a WhatsApp message.

I understand that WhatsApp is an eligible medium for the said notice, as per the Electronic Communications and Transactions Act, 2002 No. 25 of 2002.

Please confirm whether my understanding is correct or not!