The follow-on public offer (FPO) of Power Grid Corporation of India Ltd (PGCIL) will open on Tuesday.The FPO is for its 17 per cent stake sale and is expected to raise Rs. 7,083 crore.PGCIL plans to utilise the proceeds partly to fund its 27 transmission line projects worth over Rs. 48,354 crore.The FPO will be open for institutional investors till Thursday while for retail category investors and employees, it will close on Friday.