The BJP has next to Zero chance to make it alone in Tamil Nadu as a party. The next best approach is to ensure the support from TN's two main Parties AIADMK and DMK . AIADMK is already with them, so now helping to save the chief accused in the scam (the main investigation isn't over yet, this CBI court ruling can be challenged too) who both are from DMK, will ensure the BJP gets free reign in TN as well as crucial support in the Upper house from the DMK.
But the 2G scamsters walking free will dent BJPs credibility hugely . Let's see if they let it happen.