First day early morning is the best time. Being first sets the agenda and since there is less candidate at that time, so your low experience/ relevant skills is bound to be overlooked in the initial enthusiasm.
If possible, have an existing employee's name on the resume. Like for the hcl walk-in, a referral name of an hcl employee, will increase your chances of getting to sit for an interview. Even if your experience is less, a referral from the company carries more weight and HR is more reluctant to turn you off.
Keep your first page of the resume relevant, all your relevant skills, experience, projects should come at that place. They should be up and front. During walk-in's the hr won't have time to run through all the pages of your resume, so highlight the relevant experience and have the numbers boldly displayed in the first page. This not only highlights your resume, but increases your resume's chances to stay a little longer in the recruiters mind.
Follow this simple 'rules' and you will have a much better experience of the walkin's.
And one more thing, always go to a walkin. Whatever be the experience of your previous walkin's, go to a walkin if you know it's in your domain. Don't worry about years of experience or skills, if its in your domain, its worth going to the walkin than sitting at home.
You will always learn something and if the time and opportunity is right, you might end up with a job offer. I know people who got job just because they decided not to sit at home.
In a latter post, I will discuss how to update your resume for a walkin, so stay tuned.