You can save tax upto Rs. 46,350 per year by investing in ELSS funds if you invest Rs 1,50,000 and you fall in the highest tax bracket of 30%. Tax saving will be proportionately reduced subject to the taxable income and investments.
The tax benefits are as per the current income tax laws and rules.

Note that there is no limit to the amount you can invest in ELSS mutual funds. The limit is only for the amount that is eligible for income tax deduction. For eg.- you can invest Rs 2,50,000 in ELSS funds, but you will be eligible for tax exemption only on Rs 1,50,000. The remaining amount will be taxable.