If you have made Delhi your ‘home’ and intend to stay there throughout your life as well as you have left Amroha completely and do not intend to stay there, then as the question mentioned above whenever you visit Amroha to see your parents then you shall do qasr there, save in case you intend to stay there for fifteen days or more. But if you have not left Amroha completely rather you intend that sometimes you will stay in Amroha and sometimes in Delhi then in Amroha being your hometown you would offer full salah in each case.
Also see Dur al-Mukhtar with Shami (2/614,pub. Zakaria)
Allah knows Best!
Darul Uloom Deoband