Please tell me how
To apply for written test (sample paper )
In merit nation
Where to write??

Dear Student, 

Written Test are basically for your practice. Here, you do not have to write the answers online rather you need to practice in your own notebook. After completing the test, you can cross-check your answers provided on our website. 
In case of any doubt, you can always refer to the ask and answer forum of the website. 
Regards