UNCTAD has a very good database on BITs which is available here. 

IIA Mapping Project

The IIA Mapping Project is a collaborative initiative between UNCTAD and universities worldwide to map the content of IIAs. The resulting database serves as a tool to understand trends in IIA drafting, assess the prevalence of different policy approaches and identify treaty examples.

The “Mapping of IIA Content” allows browsing through the project results to date (the page is regularly updated as the new results come in).
Please cite as: UNCTAD, Mapping of IIA Content, available at https://investmentpolicy.unctad.org/international-investment-agreements/iia-mapping

For more information:
Mapping Project page
Project Description & Methodology document