What is better solutions for complex application and databases

Respected All,

Kindly guide us regarding the Databases of MS-SQL-Server.
if we want to create the one application for the 200 colleges for students online registration/Admission.
Then what will we do?
Either create seprate one application and one database for each college
OR create the one application and one database for 400 colleges.
what is best solutions and guide
I shall be really thankfull for your kindness and suggestions.
Thank you
Mamta
Jagadhri
Distt: Yamunanagar
State: Haryana
Mob.No: 9991740135
email: mamtakuk@gmail.com