I am a single girl child with obc rank 79k+. which iiit or nit can i get?

With an OBC rank around 79k, getting top NITs or premium IIITs is difficult, but you can still get some newer/lower NITs and IIITs, especially in CSAB special rounds .

Possible options include:
• National Institute of Technology Sikkim
• National Institute of Technology Mizoram
• National Institute of Technology Arunachal Pradesh
• Indian Institute of Information Technology Manipur

You may get branches like Civil, Mechanical, Electrical, or lower-demand branches depending on counselling rounds and seat availability. CSAB rounds will be very important for you.