Supergirl has been renewed for season 6, but It is anyone’s guess when it will release beyond mid-season 2021. This is due both to delays in filming caused by the spread of the COVID-19, and the pregnancy of series star Melissa Benoist. Supergirl was officially renewed for season 6 in January 2020, along with all the other Arrowverse shows, It is unclear, however, precisely when season 6 will start and on what right it will release. Supergirl was not on the schedule of spring 2021 releases, is set for a mid-season release like Legends of Tomorrow.
According to actor Jon Cryer, who acts as Lex Luthor, parts of the original finale were filmed and used, but whole new scenes were written around them. The main threat of Supergirl season 6 is unknown, but some major changes have been set-up for the cast.
The filming of season 6 of Supergirl has not commenced yet so it will be tough to predict the plotline of Supergirl season 6 before the filming even begun.
There has not been any official announcement regarding the cast of Supergirl season 6. The streaming of Supergirl is available in the official site of The CW, Netflix, and Amazon you can watch all the previous as well as ongoing season 5 from there. Season 5 had to be forcibly cut short and the finale had to be written due to the COVID-19 pandemic. And It is going to along wait before season 6 gets to see the light of day.
Owing to its popularity and steady ratings, the network recommissioned the show for season 6 on January 7, 2020. Under normal circumstances, the show would’ve have been slated for a release in October 2020.