You'd better get a plan together for some serious side lighting if you have 6 three foor indicas,they're gonna get every bit of 5 ft tall & seeing that you let them get as large as they allready are i'd bet they are bushy as all hell.
If i were in your shoes i'd start training them to be tied down twords the pot over the next two weeks & round up some good side lighting & get it in place before you start flowering,even if its some cheap ass T-12 shop lights from home depot because your going to need alot more light,by the time the plants stop their growth spurt your light will be right at the ceiling & will not be enough light past about half way down.
Ive done monster plants like yours before,it wasnt an easy task either.