In that case you are following correct procedure only. Use RMA for J1I5 updation.
Ensure the movement 101 type is assigned RG1 in J_1IMVMT table.
Also check the number ranges for J_1IRG1 object in SNUM transaction. You should maintain the number ranges such that it serves for entire fiscal year.
Check the current number range in SNUM transaction for the said object or check the Number of entries in table J_1IRG1 for the said object and ensure the number ranges are not exhausted.
To avoid the Interval rolling again from the beginning you may try to tick the "No interval option" for the Number range object in SNUM if really required.