Hi there, these are the links of websites where you will get authentic information about all the admission details you must know. 

• Careers360 Article about TIET [Read this first]:    https://engineering.careers360.com/articles/tiet-btech-admission
• Thapar University Official Website [Opens the link for the online application directly]:   http://admissions2018.thapar.edu/online-application-form.php?_ga=2.30093052.2123047454.1527055744-1179669165.1527055744  

Please revert if you have any queries. All the best!