Is fifteen lakhs INR the amount I need to show in my account for Ireland visa?

Yes, ₹15 lakh is more than the minimum required to show for an Ireland student visa.

You must demonstrate immediate access to at least €10,000 (about ₹10.99 lakh, subject to change) for living expenses, in addition to your tuition fees. This applies to courses longer than eight months.

Make sure the funds are readily accessible and not tied up in fixed deposits or unexplained large deposits.