We followed the instructions, that are available in the ResourceKit/Readme file. But our PostGresql doesn't have the lib folder so we ended up creating a lib folder and then updated the configuration file. So even after this the when we tired installing the PLJava it failed for us with the following error message.
We got to know through an SR that PLJava installation on Postgres can be skipped if we ensure that we are not reading blob properties using sql queries. So we went ahead without PLJava installation on Postgres and setup Pega.