Thanks Tom and Peter. I tried installing the latest version oracle_fdw-1.5.0 and now I see below error:
-bash-4.1$ make
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -g -O2 -DMAP_HUGETLB=0x40000 -fpic -I/u01/app/oracle/product/
12.1.0.2/db_1/sdk/include -I/u01/app/oracle/product/
12.1.0.2/db_1/oci/include -I/u01/app/oracle/product/
12.1.0.2/db_1/rdbms/public -I/usr/include/oracle/12.1/client -I/usr/include/oracle/12.1/client64 -I/usr/include/oracle/11.2/client -I/usr/include/oracle/11.2/client64 -I/usr/include/oracle/11.1/client -I/usr/include/oracle/11.1/client64 -I/usr/include/oracle/
10.2.0.5/client -I/usr/include/oracle/
10.2.0.5/client64 -I/usr/include/oracle/
10.2.0.4/client -I/usr/include/oracle/
10.2.0.4/client64 -I/usr/include/oracle/
10.2.0.3/client -I/usr/include/oracle/
10.2.0.3/client64 -I. -I./ -I/opt/postgresql/9.6/include/postgresql/server -I/opt/postgresql/9.6/include/postgresql/internal -D_GNU_SOURCE -I/opt/local/Current/include/libxml2 -I/opt/local/Current/include -c -o oracle_utils.o oracle_utils.c
oracle_utils.c:22:17: error: oci.h: No such file or directory
oracle_utils.c:35: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘err_code’
oracle_utils.c:48: error: expected specifier-qualifier-list before ‘dvoid’
oracle_utils.c:69: error: expected declaration specifiers or ‘...’ before ‘dvoid’
oracle_utils.c:69: error: expected declaration specifiers or ‘...’ before ‘sb4’
oracle_utils.c:69: error: expected declaration specifiers or ‘...’ before ‘ub2’
oracle_utils.c:69: error: expected declaration specifiers or ‘...’ before ‘ub2’
oracle_utils.c:69: error: expected declaration specifiers or ‘...’ before ‘sb2’
oracle_utils.c:70: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘checkerr’
oracle_utils.c:72: error: expected ‘)’ before ‘*’ token