After any LOKPAL Bill is passed, it's legality will be tested in Courts.
The Court will struck down those provisions which may be violative of Basic Structure of Constitution.
1) Judges of High Court and Supreme Court are Insulated from any kind of pressure. Any provision which provides for issuing notice or making them vulnerable to fear being investigated, will be struck down by Court.
2) Lokpal is a State Subject. Parliament cannot force each and every state to accept its Central Lokpal Bill. Such provision violates basic structure and can be struck down by Court. It should be, will have to be, left open to States to accept Central Lokpal Bill or not.
3) No person can be subject to DOUBLE JEOPARDY. It means no person can be tried for same thing twice. Where there are provisions of Inquiry, another provisions, a Duplicate or Superior inquiry by LOKPAL, will not hold good.
4) Crime investigation is a State Subject. No Lokpal can have power to investigate anything relating to any State without permission of that State.
5) No authority can be created which may have power over Members of Parliament or State Legislatures. They cannot be made subject to any possible pressure from any power blocks. Such is the principles of Democratic structure.
6) There are authorities, Like Election Commissioner, CAG etc, which cannot be removed except by impeachment by Parliament or State Legislatures. No authority can be created which can bring pressure on them.
Then what is possible?
That is what is required to be worked out.