unlock mobile sony sk17i from too many pattern attemps

You can check whether or not the phone is "hard locked" as a result of incorrectly entering an unlock code.

tap the following in - as if you were dialing a number to make  phone a call...

*#*'#7378423#*#*

A new "hidden" menu will appear.

Tap on "service info"

Tap on "SIM lock"

Look at the entry for "Network" - there's a number after it.   That number is how many unlocking attempts you have left - so if it shows zero - "0" - then you'll know that you've reached the limit for unlock code entries - i.e.

[x] Network 0

If it shows a number higher than zero, the problem lies elsewhere.

Also - when looking at that "Network" entry, there are brackets in front of the name that will look something like this...

[x] Network 5

If there's no x in those brackets, it means that the phone is already unlocked, e.g.

[] Network 5 - that's an unlocked phone which may also be why the phone can't be unlocked - it already has been.