I am Indian with Irish visa Short-stay visa (under BIVS). I am going to Dublin from Bangalore, India. I have booked flight (Emirates) from Bangalore to LHR London Heathrow airport and have booked separate flight from LHR to Dublin with Aer Lingus the same day as arrival. Do I need any type of visa to collect my baggage and again checkin in a different terminal in airport in London?
As stated by Timatic, the database used by Airlines:
Passengers may make a landside transit if holding a valid biometric visa issued by Ireland (Rep.) endorsed "BC" or "BC BIVS" and traveling to Ireland (Rep.).
The GOV.UK Website confirms the same:
You might be eligible for ‘transit without visa’ if [...] [having] an Irish biometric visa (marked ‘BC’ or ‘BC BIVS’ in the ‘Remarks’ section) and an onward flight ticket to the Republic of Ireland
Now, while both sources only state this applies when going to Ireland, the reverse is effectively true as well. The reason being, you do not clear UK immigration when arriving from Ireland, so you just walk to the baggage claim, collect the baggage and clear security.