Can I use the internet source for supporting a data or statistics in writing an wiki article?
The Internet is not a single source: it would depend on the specific Internet site. A general rule of thumb is that .gov or .edu sites tend to be more reliable and .com sites less reliable. Peer reviewed articles are extremely reliable. There are some specific things you can look at to evaluate the reliability of an Internet or any source on the 5 Steps to Evaluation in our Information Ethics LibGuide (link below).
In the end, it depends on your instructor and assignment, so double check with your instructor.