under your education heading in your resume you can state your average score per 100 or whatever CGPA standard adopted by your uni, make sure its some standard and easily understandable.

Education
University of Some-random-place (study period)
Course
Average Score: ##

College Pre-U / diploma (study period)
Course
Average Score:

Depending on how you arrangement your headings i.e. education/ past work experience / co-curricular activities / references / skills and misc , if you have a very outstanding education performance, you'd list it first, otherwise put whichever category you have the most positives to show for first

If they did not ask for a academic transcript, your option whether or not to attach it behind your CV
If they ask for certain documents that does not include transcript, don't include it, average would suffice
If they ask explicitly for result slip etc, then include it.

sorry about that I will attempt another response, I think your query's answer will depend on the form of application. There's a few

Application through
Direct Mail to the employer
Email to the employer
Employer/3rd party career application website

For direct mail, you just include it in the same envelop and need not mention refer to your CV since its all hard copies unless you included a cover letter then you can mention it in your cover letter. You can do at the end of your letter: I have also attached a copy of my academic transcript for your kind consideration. Thanks etc etc

For email, mention the same thing as above in the body of your email

Employer/3rd part website: usually they will ask you to upload a transcript, otherwise leave it out (unlikely tho)

hope that helps