schooling advise for my child (Brussels)

Dear friends,
my son is 4 years old.. iam an indian and i have a local job here.. Now for the primary school i have to put my child in dutch/french school.. I dont have longer plans to stay in belgium may be around 3to 4 years i will stay in belgium and then back to my home country.. In my home country the mode of education is in english.. So iam looking in brussels for an english schools so he can adapt quickly when he returns to india.. But i enquired about the international schools.. its very expensive and iam sure i cannot afford.. I heard about bilingual schools that is also little expensive - iam thinking..
do you suggest any other options and advise me the better options.. thanks in advance for your replies.

Have a nice day ahead friends,
kumar

Have a nice day ahead..