There are no freely available published data on consolidated results and practically every free source uses standalone. That is what led me to publish consolidated Nifty PE every quarter here Nifty PE.
The question is not one of efficacy but of accuracy. The value of a company to its shareholder is what the company and its subsidiaries earn, not just the company. I had written about it here A company is known by the company it keeps.
Typically for Nifty,there is about a 20-30% difference between the two, which is big, so a focus on standalone will overstate PE et al to that extent.