Hi Saravana,
Are you using the haven package function write_sas() to produce your files? I notice that the write_sas() documentation says, "write_sas() is currently experimental and only works for limited datasets", so it may not be much help in your case.
I am not a SAS user but I see that it can import CSV files - would using that file format solve your R-to-SAS transfer problem?
HTH