B.Arch doesnt have lateral entry. You have to join the first year and hence it cannot be a lateral entry. There is no lateral entry, The Admissions are to the first year B.Arch programme. However, diploma holders are eligible to apply along with 10+2 candidates. You can check the further information with the given below link.

http://www.sirjjarchitecture.org/admissions.html

Good Luck!