I have posted extensive reviews on schools 1 to 4 in your list. Orchids is new to OMR and seems to be a chain of schools. BVM Global is not the same as original BVM in Adyar, there is no connection between both.
Babaji is the best amongst this list hands down....however please take the time to visit every school and evaluate for yourself.
Hi any recommendations on cbse and icse schools in and around omr for grade 3
I would recommend DAV pallikaranai if you are staying near thoraipakkam