Usually after buying a prepaid plan I do get about 995 approx sms in the plan , when seeing twillio the estimate sms cost is ₹4 , so can we just use the 995 available in our plan somehow :)
When it comes to sending messages using Twilio, you generally cannot use your own personal phone number directly. Twilio provides virtual phone numbers, known as Twilio phone numbers, that you can use to send and receive messages. These are separate from your personal phone number and are used exclusively for your application's communication needs.
There is the option of porting your phone number to Twilio and send messages then but I don't think this is what you're looking for.