Will

Probating of the WILL has to be done by the beneficiary mentioned in the WILL.

Which ever beneficiary approaches the court will approach the court in whose jurisdiction he is resident.  Other beneficiaries / legal heirs will be made parties to the probate petition and they will appear in the court where the probate petition has been filed.  Decision by a Probate Court is final and at best it can only be appealed against.

It is not necessary that the probate petition has to be filed at different states/courts under whose jurisdiction the property is located.

After writing the WILL, if you want to change the proportion of distribution, you can write a FRESH WILL, after cancelling the earlier WILL.  In that case, the last written WILL will have effect.  (Normally one will make CODICIL for making small corrections/modifications in the already written WILL.  But this will create some confusion and problem in case the CODICIL is not properly or if both tthe original WILL and CODICIL are linked properly.  Therefore, it is advisable to write a FRESH WILL in case any modification has to be done.)