hello abhinav,                                                                                                                            The cutoff for the 10+2 btech entry is not officially announced, but you will be getting a call up letter for the SSB if you have appeared for JEE mains exam. As the instructions clearly says that the candidate must have appeared for JEE mains, that's the only thing they want. But to be on the safer side I would like to say that my friend who scored 7 marks  I repeat 7 marks for JEE mains(approx 1000k + rank) had got his call letter.
So just chillas getting atleast 7 is easy
Just concentrate on your SSB preparations
All the Best