GPA conversion

[bhakk]

Hi,

I am from India and passed my graduation with 69.6% from Uttar Pradesh technical University, Lucknow.
In my first attempt while filing the GMAT form, I used the percentage to GPA conversion table given on www.mba.com and convert the 69% = 1.9 GPA.

I have my second attempt in Aug end and while surfing on internet I came to know that GPA conversion process is different and is done by your university/college.

Now, i have 2 questions :
Will I be able to change my GPA during my admission process?
and
Should I go with the same GPA (as calculated using mba.com)or should I go to my college/university for GPA conversion?
Thanks.