Rephrase your question, not sure what your asking.
What I want to do is, I want to select largest A0 sheet to have a clear views of the drawings. After completing the drawing in A0 sheet, if I want to reduce the size (let we say A4) to get a print out. Is it possible to do so?
In this case paper and drawing have to be reduced by same proportion.
There is no requirement of reducing the proportion of views based on sheets, initially based on the sheet selected you have to fix the scale of views but while printing, check the preview, and if there are any modifications to be done then go to print properties
Zoom settings -> Normal/Fit to Paper size
Margins -> Use Printer's Margins
Page Setup -> Scale and Resolution -> Scale to fit
Maintain the above settings and print according to the size required.
As per Dan Pihlaja you can save as Pdf and save it, such that you can able to print in any size as per your requirement.
Hope your problem will get solved
Naga Ranjithkumar A
Yes, you can change to a different sheet format (for a smaller sheet), but you'll also need to change the sheet scale, assuming your drawing view is set to sheet scale. If it's set to a custom scale you'll need to change that. That will make it fit the sheet.
The whole reason to make a drawing is to print it out.
I use the D size and B size (similar, but not exactly the same as A3 and A1 sizes). Then I print everything on a 11"X17" printer. It automatically scales rather nicely.
Basically, my process is, once the drawing is complete, to save it as a PDF and then just print the PDF file.