Inter corporate investments

A Public ltd company wants to invest in a construction project of Private Limited Co., Whether it is possible for private limited company to have investment from outsiders?? If yes than by which route or under which section? if no, than what is the possible way to investment in private limited company, where there is no common director in the management of the companies, since the articles prohibits any invitation or subscripttion from the outsiders. The net worth of the public company is 60 lacs and investment proposal is for Rs. 1 Crore.   Plz advise the possible route..