JEE

Indian Institute of Science accepts admission based on NEET and JEE for the BS program. But note that for the B.Tech. programme, JEE advanced is the only channel of admission and NEET students can not get admission based on NEET scores. Also note that even NEET students must have Mathematics in their 10+2 to be eligible for IISc.

The following colleges can be the good options.

1. SLIET Sangrur
2. IKGPTU Jalandhar 
3. SMVDU Katra
4. NIFTEM Sonepat 
5. CIT Kokrajhar 

You can get the following NITs as under

1. NIT Srinagar CSE
2. NIT Rourkela Chemical 
3. NIT Calicut Civil 
4. NIT Warangal Civil
5. NIT Jalandhar Elect or Mech 

For getting admission to Delhi Technical University for a Computer Science course without JEE I don't think there is any way. I also cleared JEE with 99.2 percentile and applied for DTU or many of my friends studied CSE in DTU with their JEE Mains rank so, I don't think without a good JEE rank you get admission to DTU CSE branch.

Tes, You can get admission to B.Tech in information Technology with JEE Mains B.Arch score at Govind Ballabh Pant University Based on your JEE Mains 2 papers 70 out of 200.

Yes, you can get into Devi Ahila Vishwavidyalaya on the basis of JEE exam for its B.Tech programme. The eligibility criteria for its B.Tech programme includes JEE Main and to have passed 10+2 from a recognised board.

Clearing JEE Mains isn't mandatory for CSE at Chandigarh University. Instead, CU requires its own entrance test, CUCET, for BE CSE admissions. JEE Mains rank holders up to 50,000 are exempt, with top 25,000 ranks eligible for a full scholarship and ranks 25,001-50,000 receiving a 75% scholarship. Eligibility includes 10+2 with Physics, Mathematics, and one additional subject like Chemistry or Computer Science, with a minimum of 60% aggregate marks. 

The CUCET syllabus varies for Non-medical (English, Physics, Chemistry/Computers, Mathematics, Aptitude) and Medical streams (English, Physics, Chemistry, Biology, Aptitude).

Use Shiksha's JEE Main Rank Predictor tool. You need to enter only percentile you obtained. NTA usage the following formula uses for rank calculation from percentile.

((100-P)/100)*N+1

Where P denotes NTA score and N is number of students

Yes, there is a possibility that you can re appear for the improvement exam. But, it is to be noted that this will happen only if your board allows for it because second attempt of improvement exam is held at the same time of the general board exam.