This time they are calling to verify filled details for tablet. I have fortunately received call on 2nd attempt. Might be you will not receive call and directly recieve budd or Tablet but in other case stay vigilant
I would suggest you to go through step by step guide available on SAMMOBILE or XDA developer first before performing flash as any wrong step will result in bricking your device.
First thing first you need to understand you have brought this handset from Malaysia so the software version it has on it can only be updated via OTA in Malaysia. but as this handset is currently used in Pakistan so the CSS is mismatch with Pakistan ...