Hi, Ostine Paul                                                                                                                                   The mocktest for jee mains have not provided yet nta (national testing agancy)so that prepare for jee mains is contant books very helpful have ncert books of 11 and 12.           

Jeemain mock test has started acrooss various centres and is common for both January and April attempt. All dates and rules shared below. 

https://engineering.careers360.com/articles/jee-main-mock-test

One must prepare from NCERt books and also use reference books Like OPTandon for Chemistry, IE Irodov for Physiscs and RD sharma for Mathematics. 

Practice previously years papers and scrutinize weak sections and revsid them regularly . 

Solve all doubts and have good grasp over fundamental .