Hi Sushant,
Visit ' Adwords conversion tags' tab under 'Tools and Settings' . Select the already created (In google) conversion name/conversion category by selecting the check box and click on 'Get Tag' link. If you dont see the conversion tag/name/category listed in AMO, you can add it by clicking and following the steps of 'Add Conversion Tracker'.
Hope this helps.
Regards
Nidhi