Guru Gobind Singh Indraprastha University

The main campus USBT(University School OF Biotechnology) admission process requires a rank below 150-170 for Delhi GENERAL and 50-70 for Outside DELHI GENERAL.

If you are from Delhi and talking of engineering college, you might even get the main campus USICT which is the best college among all but only in the spot round. The college rankings are as follows:
USICT : University School of Information Technology
MAIT : Maharaja Agrasen Institute of Technology
BVP

For taking admission in IPU, you have to appear for a separate exam which is IPU-CET carried out by GGSIPU.
For eligibility criteria please refer:-
http://www.ipu.ac.in/pubinfo/admission2018/adm2018main/ADMBRO2018A_190218.pdf.

Admission in IPU is done on the basis of a separate exam IPU-CET conducted by GGSIPU.
For eligibility criteria visit: http://www.ipu.ac.in/pubinfo/admission2018/adm2018main/ADMBRO2018A_190218.pdf.

For main campus ,USMS(University School of Management Studies), IPU the OD rank should be below 400 and delhi below 700.

Yes, there is no such criteria. Any branch student can take admission.

I advice you to please go through the official website for eligibility criteria.
http://www.ipu.ac.in/pubinfo/admission2018/adm2018main/ADMBRO2018A_190218.pdf
Follow the brochure.

Every institute has different eligibility criteria for the admissions. I advice you to please go through the official website for eligibility criteria.
Link: http://www.ipu.ac.in/pubinfo/admission2018/adm2018main/ADMBRO2018A_190218.pdf
Follow the brochure.

You can get USBT(University School Of Biotechnology) at the main campus.
Outside Delhi(gen) :rank goes between 50-75.
Delhi General: rank should be less than 150.
You can still hit for spot round.