I have just started investing in stash away robo advisor and I came across RSP from the different banks that do ETF. Should I also look into RSP and invest in it as well?

Generally, I find that bank RSPs are quite hefty in terms of charges levied for each transaction. For example, DBS charges a sales charge of 0.82% PER TRANSACTION for their RSP. I'm sure since you're using stashaway, most robos charge less than that for a whole year of management LOL.

Moreover, many bank RSPs are quite limited in scope, keeping mainly to REITs, STI or bonds. I feel that robos give a much more comprehensive and diversified approach. After all, Singapore's economy is very small compared to the global economy. To have let's say, 50/50 split between the SG stocks and global stocks would be overweight on the Singaporean economy.

One RSP I think worth mentioning is from FSMOne, which allows investing in a wide variety of US ETFs, including the popular VOO and even thematic ETFs such as semiconductor ETF, SMH. Moreover, the comms are relatively low at 0.08% min USD1! In a sense, you can also get fractional shares this way since you can invest in ETFs like VOO with a min investment of SGD50 (when the price of VOO is ~USD380+).

But I think it's definitely ok to continue what you're doing with the robos. Investing solely with robos is a perfectly alright strategy after all.