As you have mention that you are looking forward for investment so according to me panchkula is best option but if you will find panchkula is bit costly or any other issue zirakpur or manimazra will be better.
Mullanpur is a very posh locality. And well connected with the other parts of the city. It is well connected by trains, buses and public transports. Transport facility is also good in this locality. School, bank, ATM and hospital are available nearby the locality.