Eleven is WAY too many - do them in batches, you would do better to concentrate on four at a time - that is what the manufacturers of 120cm sq tents suggest.
I have the same tent and light as you and I reckon at the very max you can have 6 plants in there - I currently have six - four normal feminized and two autos - in mine, but they are just seedlings at the moment. As they get older I think I am going to have space troubles, but my plan is this (hope it helps):
- The two autos are placed underneath where my carbon filter is, as they are going to grow only 1-2 feet.
- The autos should hopefully be ready to harvest around the time I flip the tent to 12/12. If not they will get a very few days / weeks of 12/12 and I doubt this will hurt them that late in their lives
- Once harvested, the tent will have more room for the other four.
- I am not afraid to cull plants if I find I have no room, and you would do well to think along the same lines - try to plan for which ones you want to keep the most. I know my Super Lemon Haze plants are my priority. I would kill everything in my garden to keep them if I had to. I hope I will be able to muddle through with all four. The non-SLH plants will harvest around 3-4 weeks before the SLH so again that gives me more room to make for the big girls.
I hope this helps.