The stress is given on c,data structure & java(if applicable).Code may b asked may not be,but its advisable to illustrate the solution(s) flow chart or using functions.
as written in my CV,i was asked questions from C,C++,Core-JAVA & HTML.
studying OOPS will be very useful for tech. interview.

I was asked one of the most difficult(yet simple) question-
DESCRIBE YOURSELF!!!
answered it n got my chance to take him(it was a 1:1 interview) to my hobbies & believe me it was a HR interviewer asked me the definition of Hard Rock music!!!
its not fake...
remember,b confident throughout the session.Stick to whatever you say.

Be confident,
But Over-confidence can be lethal...

60out of some 290 students made their way through the aptitude test.Finally 59 got selected after the interview.
i had considerable low marks through out my college life,but what helped me a lot was the communication power of mine.