yes you are definitely eligible for this course in this college but since seats are limited to 40 only,  chances are thin. But I can't confirm. Anything 

But I would like you to know that previous year cutoff for this course in this college was 72 merit marks for General category

 Forsure , there are chances of geting admission in b arch as you have scpred a good meri score to get elibile for spa mysore. so need not to worry you will get admission forsure. all the best have agreat future ahead.