Treatment of investment

You can re-group it by showing it under the ehad Fixed Assets.  Also as there is no depreciation applicable to Land, there would not be any issue of adjusting the depreciation for the period the land was purchased & showed as Investments till the date it is shown as a Fixed Asset.

I don't think that u r required to do any legal formalities.  however in the Notes to Accounts you can mentione this point.  Let's wait for other expert views.