whatever is the case, its not racism. Racism implies its based on race and if they treat the Sri Lankans okay, then it cannot be racism.
Perhaps they do treat indians badly, but thats not racism. Thats probably based on their statistics of what the people above mentioned. Unfortunately, most of us cannot help you on how to get through the interview.
While, I don't doubt individual people in CIC (or anywhere) could be racist, I am in no doubt that CIC as an organization/institution is not racist, but that is my opinion and really not based on anything because I don't have much experience with them except looking at statistics.