You need to intimate your bank of your change of status and convert your NRO account into a resident account. The faster you do it better, because tax liability in a NRO savings and a NRO fixed deposit is higher than for a domestic resident.
You can hold FCNR deposits until maturity. On maturity take steps to convert it to a rupee account.
You need to convert the same into a resident account on return.
Shares, securities and mutual fund units
Please intimate your broker and depository participant of change in status. NRIs have to go through the portfolio management scheme, while the change of status means you have lesser hassles, while trading and holding shares. It's best to close your trading, PMS and DP account and open a fresh one as a resident individual.
Other points to remember
1) You can open a Resident Foreign Currency Account with an authorised dealer and can hold forex money denominated in foreign currencies.
2) If NRI returns to India with the intention of permanently settling in India, the assets brought by him will be exempt. Also, the money and the assets acquired from the money, brought by NRI within one year after his return, will be exempt.
3) A NRI returning to India who has been a Non Resident for nine years or more, then for 2 successive years he shall be a resident but not ordinarily resident (RNOR).
4) If you are likely to earn heavily from fixed deposits and rentals, than you should plan your return during the part of the year, so as to reduce your tax liability.