Hra for two cities

Yeah , you can as nothing is mention in section 10(13A about this disallowance,

However u can calculate both  hra exemption  separately(monthly)

then add both ,and get exemption

HRA is exempt under section 10(13A) to the extent of the minimum of the following three amounts
 

• 1. Actual House Rent Allowance received by the employee
  2. Excees of rent paid for the accommodation occupied by him over 10 % of the salary.
  3. 50% of salary where the residential house is situated at Mumbai, Calcutta, Delhi or Chennai and 40% of the salary where the house is situated at any other place.