The organisation said the bank’s proposal was opposed by the vast majority of rural Scots who will be affected.
The closures, which would see the loss of 158 jobs, were driven by the fact more people are choosing to bank online or on mobile phones, according to RBS.
However the SRA pointed to its own research, which it said highlighted the negative effects of shutting branches in small towns and villages.
Its questionnaire on the closures, sent out through its mailing lists and social media channels, was completed by 1,100 people.
It found 95 per cent of those affected believe the closures should not go ahead.
Just over half cited concerns over increased isolation if the branches close, while two thirds were worried about being unable to deposit or withdraw cash.
The SRA said: “The closures - which are predominantly in rural areas - discriminate against rural communities, vulnerable people, small businesses and demonstrate a complete lack of care and compassion on the behalf of RBS.”
The organisation’s chief executive Emma Cooper added: “The proposed branch closures will have a huge impact on Scotland’s rural communities, our high streets, tourism and will impact most severely on the vulnerable.
“RBS is not the only bank that has been closing branches, but many of these closures will the last branch in town closing, leaving communities and business owners with no local alternatives.”
Westminster’s Scottish Affairs Committee is due to take evidence on the issue on Wednesday.
Alongside SRC, MPs will also hear from trade union Unite, which has described the closures as a betrayal, and accused banking chiefs of playing down the scale of job losses.
Meanwhile, a written submission from the Federation of Small Businesses (FSB) said its analysis showed RBS has cut its branch network by 70 per cent in the last five years.
The committee will also hear from Jane Howard, managing director of personal banking, and Lee Matheson, chief executive of personal and business banking at RBS.
A spokesman for the bank said: “Our business banking teams have been proactively contacting customers who use these branches regularly to advise them of the closure, what it means for them and the alternative ways to bank when the branch closes.
“As customers continue to change the way they bank with us, we must change the way we serve them, so we are investing in our more popular branches and shaping our network, replacing traditional bricks and mortar branches with alternative ways to bank.
“Our fleet of 20 mobile branches in Scotland serve over 324 Scottish communities each week through 385 stops in towns and villages.
“At a Post Office business customers can deposit funds, withdraw cash and get coinage”.