If you upgrade to JCE Pro 2.8.x from JCE Pro 2.7 or earlier, then the Columns tool will need to be added to the editor toolbar.

You can do this by dragging the Columns icon into the editor toolbar in Editor Profiles -> Features & Layout.

For example (showing adding the iframe button) - https://www.joomlacontenteditor.net/support/faq/editor/pro-buttons-missing-after-upgrade

If we center an image in column will it resize dynamically with changing screen size?

Yes. Personally I prefer to add the alignment to the paragraph that contains the image rather than the image itself. Click somewhere in the paragprah, next to the image, then click the Align Center button.

For more info on Columns - https://www.joomlacontenteditor.net/support/documentation/columns/creating-and-editing-columns