1) Install below required pkg
SUNWbtool, SUNWlibm, SUNWarc, SUNWhea and SUNWsprot
SUNWsprox
2) Install GCC
3) Download Regina-REXX-3.6.tar Pkg for regina
4) tar -xvf Regina-REXX-3.6.tar
5) cd Regina-REXX-3.6
./configure --build=sparc --enable-32bit --with-staticfunctions --with-regutil
(can get options ./configure --help)
6) make install