I want to make sure my Citizen Eco drive B612 is original? So how I can confirm about it?

I'll need more information about the watch. WR200 is not the model number. It is the depth in metres it is water resistant to.
The serial number is usually engraved on the back plate of the watch. The bit against your skin when you're wearing it. It's the number marked in red in the photo I've attached. Is this a digital watch, a watch with hands or does it have both?
Comment below with the serial number and I'll try to help you more.

www.citizenwatch.com/en-ca/support/setting-instructions/

Citizen Eco-Drive runs continuously in any kind of natural or artificial light for a lifetime of use. Fueled by light, it never needs a battery. hope this helps you..

you can download the manual from the link below
http://www.citizenwatches.com.au/products/model/CA0130-58E

Dont look any further. Send it to Citizen: Full particulars can be found here: http://www.citizenwatch.com/

There is not enough information given. Citizen is make. Eco Drive is patented micro electric system name. C650 is caliber number. C650 is fitted in to many Citizen watch models. Give us exact model name, numbers, serial, etc. - then we can give the size. For a while you can check out C650 here: http://www.citizenwatch.com/COA/English/settingsresults.asp?caliber=c650 Citizen watches here;
www.citizenwatch.com

You can get instructions from the Citizen web site.

Go to "citizen.com" and on the upper right there is a menu. Click on "technical
support" and then on "setting instructions"

Fill in the information required from the back of your watch and then click on
"get setting instructions"

Go to the "www.citizenwatch.com" site, select you area.
l
Select "technical support"

Then "setting instruction"

Enter your model number.

Could be that the watch inside and outside numbers do not match. If the dial says Eco Drive, that should be the first step. Next, find out about the 4 digit number that tells you which type we are looking at. You may want to open the back and look at the number on the watch internals. But be aware you may damage the water proof seal in doing so.
Really, you should write down all numbers you can see and send an email to citizen. They will help you.
If you need to know more about the Eco Drive, look for detail tech manuals for all types here: http://www.citizenwatch.com/downloads/tech/tech.htm
Those are great watches as long as you remember it needs light to charge.

Go to this link and pay particular instructions on how to find your watches movement or caliber number.
http://www.citizenwatch.com/COA/English/settings.asp