I need to install community extension to enterprise, before this I need to know What are the differences between Magento 2 Community and Enterprise in code wise
You should read below links before you buy it.
5) Magento2: Community edition Vs Enterprise edition (please see this as your question is already asked)
6) When to choose Magento Enterprise edition over Community edition? (I think this one you should read first, why choose EE over CE)