funny replies...
interview depends on the person. some ask technology stuff/projects you have done while others may ask CS fundamentals. knowing java is not mandatory but if you put experience in java in you resume, be familiar with the core java stuff. there will also be questions to check whether you really understand the stuff you are working on (eg a technology used in your past projects). they usually don't ask questions like how to configure x in technology y which requires remembering stuff, but the focus is on the understanding of something.
usually there are 3 tech interviewers and an average score is calculated based on their ratings.
my advice is, if you really don't qualify, don't go there by cheating.. especially for a tech lead position, work will be tough and if you don't really fit there, end of year or mid-year evaluations will be troublesome.
refresh you knowledge on above stuff and just go there prepared, it won't be a daunting experience and there are friendly people. good luck.
I mean most of the companies , have policy saying, if you leave , you have to inform that to HR before 3 months, so with all these steps and all there is so much pressure. And taking all those days as leaves 
Let's say 3 is acceptable. I can get a fair picture of what a guy knows really by talking to him for a few minutes.
