SITEEE

Yes, it is available in online format too.

It depends upon the exam and the course you are applying for. Since you have tagged Mass communication, I am assuming you are interested in it. Basic level Maths up to class 10th comes in every exam, be it HM or BBA or your Mass Communication.
Topics like percentage, ratios, time and speed come up. So, even if you don't have Maths in class 11th and class 12th, I am sure you will be able to crack it.

For the UGAT/BCA/BHM and integrated MBA courses, the best books known are R. GUPTAs master guides and solutions besides this, previous year papers and sample papers will benefit you.

SET Question & Sample Papers 2018:
Download previous year question papers and sample papers of SET 2018 for your exam practice from the link provided below. Question Papers for SET 2018 available on Shiksha will enable you to improve your speed and accuracy. You can download all last years' SET exam question papers and sample papers free of cost. You can also download preparation guides for SET designed by Shiksha experts.
https://www.shiksha.com/college/symbiosis-international-university-s-set-symbiosis-entrance-test-undergraduate-degree-programmes/exams/set/question-papers

Please refer to the link below for eligibility criteria:
https://www.shiksha.com/teaching-education/exams/Kerala-set.

SET exam is basically an exam that qualifies you for taking up appointment as Assistant Prof. No, B.Ed is not required, but you need to have scored minimum marks in your PG exam. I am attaching a sample link from Pune University that nay help you. http://setexam.unipune.ac.in/Eligibility_Criteria.aspx.

Please refer to the link provided below for details regarding syllabus of the SET exam conducted by Symbiosis center of media and mass communication, Pune. SET Syllabus 2018: https://www.shiksha.com/college/symbiosis-international-university-s-set-symbiosis-entrance-test-undergraduate-degree-programmes/exams/set/syllabus.

The exam remains the same for the different courses. Only the cut-offs changes depending on the categories.

SITEEE exam is the private exam of Symbiosis institute for admission in their colleges. SIT Engineering Entrance Exam (SITEEE) is an engineering entrance exam conducted by Symbiosis Institute of Technology (SIT) for admissions to its B.Tech programmes in civil engineering, computer science and engineering, electronics and telecommunication engineering, information technology and mechanical engineering. The exam has been renamed from SET to SITEEE recently.

I can't just simply mention a specific site to get answer key. You can simply search for it on internet.