Dear Seeker3k ji,
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=26397
All are equally entitled to Amrit Pan irrespective of their cast and creed.
If any "Gurudwara" that practices discrimination in this regard, it is then not a Gurudwara, it is something else.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=26397
It is essential that you must present yourself after taking a bath including the kesh and must put on a clean set of clothes. You must have all the 5 Ks.
In Delhi Amrit Sanchar is done periodically at Gurudwara Sis Ganj and at Gurudwara Bangla Sahib. You can find out from the Head Granthis of these Gurudwaras about the dates.