What minimum radio communication equipment is required in a homebuilt aircraft in India?
According to DGCA Rule 63 you need a radio onboard to operate both VFR and IFR 


  63. Aircraft for which radio apparatus is obligatory- 
  
  (1). All aircraft registered in India and required to be operated in accordance with VFR/IFR condition shall be provided with communication equipment which
  is capable of conducting two-way communication at all times with those
  aeronautical stations and on those frequencies as prescribed by the
  appropriate authority. The communication equipment so provided shall
  be of a type approved by the airworthiness authority of the country of
  manufacture of aircraft and acceptable to the Director General.
  
  (2).   An aircraft shall be provided with navigation equipment which will enable it to proceed :

(a)   in accordance with the flight plan; and

(b)   in accordance with the requirement of air traffic services, except
      when, if not so precluded by the appropriate authority, navigation for
      flights under the visual flight rules is accomplished by visual
      reference to landmarks at least every 110 kms (60 Nautical Miles).



DGCA Rule 9 also adds some stipulations to the operation of the radio its self 


  9. Radio-telegraph apparatus - 
  
  (1) No person shall operate radio transmitting apparatus in any aircraft registered in India unless he
  holds a licence of the type required by the provisions of Part V in
  respect of aircraft required by these rules to carry radio-telegraph
  or radio-telephone apparatus, as the case may be, and issued in
  accordance with those provisions.
  
  (2) Radio-transmitting apparatus carried in aircraft shall be operated
  under the conditions defined by the International Tele-communication
  Convention (Madrid, 1932) and the general radio-communication
  regulations annexed thereto as far as these apply and shall be
  operated only during the hours in which such operation is permitted by
  the Central Government.
  
  (3) Aircraft registered in India and required by these rules to carry
  radio-telegraph apparatus shall be fitted with such apparatus in
  accordance with the provisions of Part VII.
  
  (4) Nothing in this rule shall exempt any person from those provisions
  of the Indian Telegraph Act, 1885, and the rules made thereunder which
  require that radio-telegraph apparatus shall be licensed.


You can find the rest of the rules here. I went through them briefly and cant find a whole lot on certifying home built aircraft. Or what rules they would actually fly under. There is a short list of things related to actually getting an airworthiness cert here but it does not touch on VFR/IFR classifications related to that. 



As for the safety aspect of it, that depends on your countries aviation infrastructure and if carrying a radio benefits you. If no one is listening on the other end then its not going to add much but weight to the aircraft. From a regulatory standpoint you may need it to enter certain airspaces (you may also need a transponder for that as well) I cant find a whole lot on the DGCA website about airspace regulations so its hard to say exactly when you would need one. I can only compare it to places I have flown and here in the US while you don't legally need a radio in uncontrolled airspace its still a good idea to have one and to use it as you should (CTAF announcements, flight following if you like, 121.5 if you need it etc.)