summer internship

Dear sir,

I am a 3rd year civil engg student from NIT, Jaipur. I wish to do my summer internship at bangalore, which is my home town. I had applied to almost a dozen companies with no success till now.
Can you please advise about how to apply for a company and ask them to post me at bangalore. To be honest, I'm not aware of the procedure of applying for these. please help me out