You could try Hill stations in India, which are not cold, but chill enough to keep away the summer heat. From Delhi you could plan travel to
Mussoorie- Nainital-Auli-Dharamshala-Mcleodganj -Kufri and Munsiyari. From mumbai here are some hill stations you could plan your visit-Mahabaleshwar, Panchgani, Igatpuri, Matheran,Pachmarhi, Lonavala and Khandala, Lavasa, malshejghat, Rajmachi and Kolad. From Kolkata- Darjeeling, kurseong, mangapoo, sandakphu, Tawang, Shillong and lava. From chennai- Ooty and Kodai, Yercaud, Coorg, lambasinghi, kudremukh, Munnar, Asthamudi, Chikmagalur, Yelagiri and Topslip. However there are a few spots in India, which are warm though not cold. Srinagar-Leh-Dooars-Kalimpong-Wayanad-Kohima-Pune-Dalhousie-Nandihills and Almora. Some beaches are warm but a bit high in heat, Goa-Gokarna-Pondicherry-Lakshwadeep-Kerala beaches-Dhanushkodi-Vishakapatnam-Ganapathiphule-Maharashtra beaches.