LLP Authorisation

My Client is boarding to US, he want to authorize someone to take all the LLP operations related to ROC and Bank until he comes back. Please guide me on all procedure which is required under ROC and Bank. Please keep a note:

1. There are two partners to LLP of which both will be unavailable,
2. He doesn't want such authorized person to be a partner.
3. Authorized partner is his relative(brother).
4. He will be staying in US for about 2-3 months.