Though your English is a little difficult to understand I do appreciate your skill to speak more than one language.
Anyway, if I understand you correctly you are asking how many pixels are in a centimeter or an inch. The quick answer is that it all depends on how you set the resolution. But unless you are preparing an image for printing then the issue is irrelevant because in the world of the computer and television screen there is no "pixels per inch or centimeter". Screens have all sorts of different resolutions, displaying the same image at different DPI depending on the type of display and its settings. For example, a regular television has much less pixels per inch than a hi-definition television does.
But if you really just want to know how to set the DPI or DPC in the Maya render globals you can do it easily:
1. Go to Maya's Render Settings window and in the "Image Size" area under the "Common Settings" tab set the Size Units to centimeter or inches.
2. Then, below, either leave the Resolution Units at "Pixels per Inch" or change it to "Pixels per Centimeter".
3. Then you can set the resolution of your image by inputting the dimensions in Inches or Centimeters and how many pixels per inch or centimeter.
By default Maya renders images at 72 pixels per inch. But remember, that only applies to how how it will print out.
If you just look in the render settings you'll easily find a pre-set for rendering in A3. But the actual pixels per inch is your choice. A3 is 11.69 wide by 16.54 tall. Usually for printing images at a size like that you should have 300 dpi (pixels/dots per inch).
Once again, pixels do not equal inches or centimeters or any physical measurement. You can put as many or as few pixels in an inch as you want. 300 per inch is best for high quality prints.