We have already discussed that GST today is not a complete subsummation. Certain goods and certain indirect taxes has still been left out of GST. Petroleum represents one example, it is within GST but not effective yet. Tobacco is another example, a different example, it is within GST but also subject to excise duty.  Real estate is a third species of example. There are entries under the State Lists namely taxes on land and building, stamp duties which apply in relation to land. However, there is still a possibility that real estate or immovable property can be considered to be subsumed within GST on account of wide definition of service under the Constitution. However, these are niche aspects and I will recommend you have a look at my book for finer details.