EL venue 8 pro tablet onscreen keyboard stopped working and now unable to login

HI Guys ,

DEL venue 8 pro tablet having window 10, suddenly its onscreen keyboard stopped working and now i am unable to login in to the tablet. even ease of access onscreen keyboard option is grayed out.

I am using Outlook email to login and also have pin but  no use because can not type anything. 

Did multiple restart etc. but same state . Please suggest if any hack or if I can run the windows on safe mode etc. 

I have a Dell:mechanical keyboard but tablet don't recognize it too. 

Please suggest.