B.Arch course is in demand now-a-days due to boom in construction. If you have desired skills then there is good scope for you. There are jobs in both public and private sector. 

Getting  a good placements afer B.Arch course depends on your college/university.

You can also apply directly to the firm you want to apply for. 

Fresher student can earn a starting salary around 4 to 5 lakhs. Salary will increase according to your experience. If you have a good experience you can get a salary around 8 to 10 lakhs.

Good Luck!!