Why No Analyst Coverage for Adani Companies

5 Listed companies of Adani Group values more than $6 Billion and those companies Market-cap tremendous gained between 4 to 6 times for the last 1.5 Years, led those stocks to include in Nifty 50 index & Next 50 indices.

Having such a large valuation/growth, there is no/few analyst coverage for those stocks
what could be the reason