KerstmisNoel:
The gsm library that i am using uses software serial at pin 10 and 11 .
That seems seriously stupid, and you need to check that it is true, You might then have a look at the GSM shield. Mine has software serial on pins D7,D8, which is a reasonable pair to choose, and I thought they were all the same.
Your code, or the library can be edited if and as needs be. Notepad++ is good for editing a library.
Software serial can be used on several pins, check the data sheet. GSM shields typically have jumpers in a six-pin block. You could remove the jumpers entirely, and have flying leads going to any vacant pins available and appropriate. You might also question if you need to use software serial at all.