On the TRON network, all TRX holders can apply to be SR candidates, and are likely to become SRs or SR partners. Any TRX holder can vote for SR candidates, among which the top 27 most-voted candidates will become SRs, while the 28th to 127th will become SR partners. SRs are responsible for producing blocks and packing transactions. SR partners, on the other hand, only receive voting rewards without performing the aforementioned two tasks. All SR candidates, SR partners and SRs have the right to raise proposals to modify parameters on the TRON network.
How to apply to become an SR?
It requires 9,999 TRX to become an SR. You can apply on TRONSCAN.