UPCAT

Hello Saurav,
Please follow this link for compete detail about the college you may get according to your marks:
https://www.shiksha.com/b-tech/resources/upsee-college-predictor

Yes, you can get it but you will have to wait until the counselling. Once your rank is out, you will have a clear vision about the college that you can get into.

Counseling Registration:
In order to participate in UPSEE counselling, firstly candidates need to register online followed by the submission of counselling fee. Registration fee of Rs. 20,000 for general/OBC candidates and Rs. 12,000 for SC/ST candidates will be taken from the candidates. After successful registration, students have to appear in person for document verification round.

I have no idea about paid seat but yeah their are some seat reserved for reserved categories candidates for more details please visit UPTU official website and download pdf format of reservation broshchere.

Yes, there are:
1. Inmantec Institutions
NH 24, Near Dasna Crossing, Adhyatmik Nagar, Udyog Kunj, Ghaziabad, Uttar Pradesh 201009
2. I.T.S College Ghaziabad
Grand Trunk Rd, Mohan Nagar, Ghaziabad, Uttar Pradesh 201007
3. IMS Noida
A-8 B IMS Campus Sector-62, Noida, Uttar Pradesh 201303
4. Galgotias College of Engineering and Technology
1, Knowledge Park, Phase II, Greater Noida, Uttar Pradesh 201306
5. IMS Ghaziabad (University Courses Campus)
IMS GHAZIABAD (UC CAMPUS), NH 24, Adhyatmik Nagar, Ghaziabad, Uttar Pradesh 201015

Yes, you can get admission in the second shift.