Which of the following RNAs is not required for the synthesis of...

The process of synthesis of protein is called translation. It utilizes three types of RNA for the process:

(1) mRNA: It carries the message for a sequence of amino acids in the form of genetic codons.
(2) tRNA: It carries amino acids at its $3 '$ end in charged form. Also, it has an anticodon loop to identify codons of mRNA.
(3) rRNA: It forms the ribosomal subunits and hence is called ribosomal RNA. Ribosomes are called protein factories of the cell.

siRNA or small interfering RNA is not used in the protein synthesis mechanism, it interferes with the synthesis of proteins.