Hello, I need to find out if I could get a 5 to 6months Dutch Learning course in Belgium (preferably Flanders area) from April to August. Please kindly share your ideas of institutes or learning centers through which I can learn dutch for that period of time.

Regards.

https://www.google.com/#q=Dutch+lang...ams+in+Belgium

'(preferably Flanders area)'
that's a good idea of you want to learn Dutch
You can find Dutch courses in Brussels and Wallonie, but everyone on the street will speak French.

No personal experience, but try Huis van het Nederlands.
http://www.nt2antwerpen.be/
It's a Flemish government organisation. They will be able to find a course that suits you.

Can I ask why you are learning Dutch in Belgium?

Good for you, wanting to learn Dutch. Good luck getting a visa. Not simple.

Thanks to those who gave helpful links. God Bless you.

Before you pay for any courses out of your pocket, check out the info pages for (potential) immigrants:
http://www.inburgering.be/en

You'll probably get a free voucher for the language course, counseling, career information, and other information/integration courses.