Hello there!!
RTU Kota is affiliated to Rajasthan Technical University(RTU) kota, so the admission is done by the REAP counseliing form. REAP is the common counselling form for more than 80+ affiliated colleges across Rajasthan. The counselling  is based on the score of JEE Mains. So without JEE mains you can't appear for counselling. As you have stated that you have scored 48155 rank in JEE, so this is approximately equal to 108-110 marks. In colleges like RTU kota you getting CSE on 110 marks will depend on the level of competition and some luck.You can opt for CSE as first choice and IT, other branches as other choices. You will probably get a seat in 1 or 2 counselling. Form filling have been started from 30 May 2019 and last date of form filling is 29 June 2019. Academic fees of RTU affiliated colleges is 80k per annum. And these colleges also have a decent placement.

If you have any doubt related to admisiion please let me know in the comments below.