How to find intrinsic value stock holding companies?

There are many listed companies which are basically stock holding companies. They have no other operations besides trading and investing in shares of other companies. Few of them are:
hb stock holding
hb portfolio
Netflier Finco
TCI Finance

Stocks that these companies are holding have gone up significantly and hence, investment per share is much more than what these stocks are quoting at present.

For example, TCI Finance:
Market value of quoted investment: 129.59 Cr
Book value of unquoted investment: 10.71 cr
Contingent liabilities (to be deducted): 5.95 cr
Total: 134.35 cr

Total shares outstanding: 1.29

Hence, investment per share: Rs 104


But it is quoting at Rs 55 as of today.

Similarly, other stocks are also quoting much below their investment per share value. For hb stocks, see this thread

So, can we conclude that these are value picks and eventually, their price will rise to near their intrinsic value. Or is this approach of coming to intrinsic value of stock holding companies WRONG. If yes, then how can one find out the intrinsic value of such companies since PE, ROCE, etc are of little help here.