Visa Renewal in Colombo, Sri Lanka

Hello! My 3-month indian visa issued in St. Petersburg, Russia ends on 18th of January 2006. I'm willing to have a flight on 8th of January 2006 and apply documents on Monday 9th of January for 6 month tourist visa (maybe i can try for 12 month?) in Colombo, Sri Lanka... And then have a flight the next day morning (10th of January).

The questions are:

1. Is it possible to do it all in one day? I mean apply documents in the morning and get the visa 3 p.m. the same day? Then have a flight next morning.

2. Can any problems happen considering I'll have a 3 month visa that's not yet closed (or should i ask to close it in the airport on departure from India)?

3. If they see I had a 3 month visa, would they give me new one for 6 month?

4. What other problems can i face?

Thank you in advance.

It will probably take you 5 working days to get your indian visa in SL when you are not resident there.