Hello Smita! Since you have chosen the Combination of MBA+MCA course in your application form, now you have to appear for 2 exams, i.e., the MBA test and the MCA test. This is according to the general information regarding  which test to appear for, provided in the Information Brochure of the Official website of Odisha Joint Entrance Exam.
Also, there is a requirement for certain subjects and minimum marks for the paper you are opting for:
MBA
Marks required:
General category- 50%
SC/ST category- 45%
Subject: Bachelor's degree in any stream
MCA
Marks required:
General category-50%
SC/ST category- 45%
Subject: Bachelor's degree in any stream, 3 years duration must have passed, mathematics at 12th or graduation level. Business mathematics at +2 level is not allowed
According to the performance in OJEE- 2019 entrance examination, the merit list of successful candidates shall be published for admission, as per the total available seats.
Also two supernumerary seats will be given to J&K students in AICTE/UGC approved colleges.
Eligibility criteria for MCA
‌The subjects and marks mentioned above for MCA course.
‌But if the candidate has done his/her BCA/BSc ( IT/CS/IST/ITM) with mathematics subject. Then they can appear for entrance exam without mathematics in 10+2 level.
‌It has no age limit.
Eligibility criteria for MBA
‌The marks mentioned above
‌The Bachelor's degree should be completed, or the candidate must be appearing in 2019. It should be of 3 years from University of Odisha or any other university recognised by UGC/AICTE.
                                            OR
     The candidate must have passed or         appearing in 2019 for a Bachelor's degree in Engineering/ Technology/ Architecture/ Pharmacy examination of minimum four/five years in any discipline from the University of Odisha or any other university recognised by UGC/AICTE.
‌There is no age limit.

The exam conducted for MCA and MBA will be computerized.
For MCA, there are 120 questions to be answered ( Mathematics-60 and Computer awareness-60), duration of the examination will be 2 hours.
For MBA, there will be 120 questions ( Verbal reasoning-40, Analytical reasoning-40, General knowledge-10, Comprehension- 20, Computer and Business fundamentals- 10), with an exam duration of 2 hours.
The tuition fees for the respective courses will be communicated after it is approved by the Government of Odisha, and before the counseling process starts.
For further information about the examination process, download the information brochure from the following link: https://ojee.nic.in/publicinfo/public/home.aspx
All the best!
I hope this helps.