TCY Online is a test platform which even has its Android App on Google Play Store. Let me share few things about this website:
Pros
It gives you the largest pool of Curriculum from Foundation to Competitive Exams
It provides you detailed feedback about your tests or assignment
It includes topic wise tests, sectional tests and mock tests
Cons
It will never give you anything without there own benefit(i.e. It is not free)
It is known for its incomplete publishing which is strongly regretted by many students and parents
TCY online only provides analytics and do not provide any course or study materials
Many inconvenience in Mobile app like(Test over before time, etc.)
So, If you have nice bank balance to spend it only for analytics. then I will say GO or else if you want some good study materials along with video lectures and tests. I would strongly oppose TCY online and recommend you to go for BYJUS, Toppr, Aakashitutor etc