KCET

Yes, you have a choice of rewriting KCET anytime as long as you fulfill the eligibility criteria that is you must have at least 45% marks (40% for ST/SC) in math and Physics along with Biology or biotechnology or Chemistry or electronics or computer Science.

In KCET, 50% from theory result and 50% from KCET entrance exams are considered according to that your rank can't be predicted because it depends upon how many students have written the exam. For assumption, you will get more than one Lacs ranking.

You should go for management seat quota. Like in Gulbarga PDA, Appa, Venkateshwar engineering college, Bangalore,
Bhimaraya Kahadre College, Bhalki etc.

Yes, it is possible. There are many ways to join B.Tech. In private colleges we have to pay amount for seats. For government seats we have definitely qualified the CET exams.

Yes, you can get easily. Yes, you can get any branch in BMS Basavana Gudi campus.

I had scored 296/300 in PCM and 162/180 in CET. My rank was 224, I was the last but one (penultimate) person to get the seat in general category (I guess the last rank to get in was around 245). This was during the year 2017 so I guess you need to get above 165/180 and 290+ to guarantee a seat.
I got my seat in second extended round. There is one more round but it is very risky to get seat at that time, you should have already joined a college by then.
Also note that in cases of tie math subject has more weightage than the others, however it's not very important.

Hi abhishek
Hello aspirant, Based on your board marks and KCET marks your rank will be in between 4500 to 5000 and these are the best colleges you can get-
Ramaiah Institute of Technology-B.E. In Electronics and Telecommunication Engineering
Faculty of Engineering and Technology, MS Ramaiah University of Applied Sciences-B.Tech. In Aerospace Engineering
B. N. M Institute of Technology-B.E. In Computer Science and Engineering
Dayananda Sagar College Of Engineering - DSCE-B.E. In Aeronautical Engineering
Sir M. Visvesvaraya Institute of Technology-B.E. In Information Science and Engineering
And if it's help you like it.

Here some college which give the admission for 35000 rank.
1. Dayanand sagar college of engineering Bangalore
2. Kalpatharu institute of technology Tiptur
3. Maratha mandal engineering college
4. Government engineering college raichur
5. Sri Taralabalu jagadguru institute of technology Ranebennur
6. Hirasagar institute of Technology Belagavi etc.

R. V. College of Engineering, Bangalore
P E S Institute of Technology, Bangalore
PES University, Bangalore
Here are the top BC engineering colleges under rank 50000 in KCET.

Sorry to say, but you can't take admission in CSE with this rank. You can look for private colleges.