You can try for Aspire Study Kanpur and Impetus Gurukul. You can also try for NIMCET Previous Papers Online for better preparation.
Also , The official NIMCET mock test is released by the conducting NIT which you can try but also focus on taking mock tests from other sources as well. As more the mocks are attempted, the better speed and accuracy you can get.
For more updates about the exam you can also visit our site : https://it.careers360.com/exams/nimcet