using index,wherecontains() need to fetch only rajini details

Can try this?

a!localVariables(
  local!x: {
    { name: "rajini", marks: 25 },
    { name: "vamshi", marks: 30 },
    { name: "rajini", marks: 40 },
    { name: "venkatesh", marks: 88 }
  },
  index(
    local!x,
    wherecontains(
      "rajini",
      touniformstring(local!x.name)
    ),
    {}
  )
)