there are many online websites providing mock test of cil ee 2020..
i will provide you the link to go the mock test web page of such a site. you can enroll yourself in that website and take the mock test series.
you can go to either of them to take the test. the test papers are based on the cil exam pattern and syllabus. to the later website the test paper programmes start only after 11th january,..
hope this information helps
all the best for your bright future..