You can apply directly from private college website like nims,sharda University, galgotia university etc.you can apply from here

https://engineering.careers360.com/colleges/ranking/top-private-engineering-colleges-in-India

BTech Admission 2024 can be done based on entrance exams such as JEE Main, JEE Advanced, TANCET, etc. Apart from these, students can also appear for state-level exams such as WBJEE, OJEE, MHT CET, etc. if you have qualified in one of these you can apply for counselling process.