coolmirror: no offense, i guess, you always have some or the other season for mangoes in india..innit?! even if you don't, South Gujarat-based Desai Fruits and Vegetables is produces all-season mangoes & is distributed all over india.
Now,I understand Avacado may not be easily available as its not commericialized in India on big scale however its grown in Tamil Nadu, Kerala, Maharashtra, Karnataka in the south-central India and also in the eastern Himalayan state of Sikkim. But if you took it for your mother,,i have no words to speak as its priceless. :)
all my best wishes for your mother. :)