how I take admission in mba ?is there any entrance exam for it or direct admission?

Hello Aspirant,
Hope you are doing good.
MBA - Masters in Business Administration is a two-year degree course.
The general MBA eligibility criteria is securing a minimum of 50% marks in graduation. Students from any field are eligible for MBA admission, but some colleges such as IIT Kharagpur require students to hold a 4-year bachelors degree. MBA has no age limit for students but certain MBA Exams like ATMA require the student to be 21 years of age at the time of exam.
Candidates willing to seek admission in  MBA colleges should register and apply for the relevant MBA entrance exam like CAT/XAT/IIFT/NMAT/SNAP within the specified registration window. Most National level MBA entrance exams like CAT, XAT
CAT -The Common Admission Test (CAT)is a computer based test for admission in graduate management programs. The test consists of three sections: Verbal Ability and Reading Comprehension (VARC), Data Interpretation and Logical Reasoning (DILR) and Quantitative Ability (QA). The exam is taken online over a period of two hours.

For more details regarding the MVA and it's admission procedure can visit the link given below:
https://bschool.careers360.com/articles/mba-admission-process

Hope this information helps you.
All the best.