There may be additional limitations for certain companies like banks, insurance companies, agric companies, and so on. I am however NOT aware of any additional share limitation put in place particularly for real estate companies. It therefore appears that the general provision under the Companies and Allied Matters Act would apply. This stipulates a prescribed minimum share capital of N10,000 (Ten Thousand Naira) for private companies and N500,000 (Five Hundred Thousand Naira) for public companies i.e. companies whose shares are traded on the stock exchange.
Hope this helps.