 HIV positive patients regardless of ART status with newly diagnosed pulmonary TB attending the TRC clinics at Chennai, Madurai and Vellore will form the study group. Those who fulfill the clinical inclusion criteria will be evaluated for eligibility to the study after signing a screening consent form. Patients willing to participate in the study will undergo the following investigations namely, sputum examination, chest x-ray, liver and renal function tests. Hematological investigations will include CBC, CD4 and viral load, done periodically at baseline, end of intensive phase of ATT, at the end of TB treatment and once in 6 months during follow-up period of 1 year. Patients getting enrolled in Chennai and its subcentres will also be evaluated for immune reconstitution inflammatory syndrome through additional laboratory investigations. If the patients satisfy the inclusion criteria, a house visit will be done by the social worker to ascertain the facts regarding living condition and domiciliary stability and if continues to remain suitable , will be enrolled into the study after a written, signed and dated informed study consent form. All eligible patients, enrolled into the study, will be randomized to receive one of the three regimens mentioned below. Patients who are ART naïve will be referred to National AIDS Control Organization NACO ART centres for assessment and eligibility for procurement of ART according to National guidelines Common opportunistic infections that could occur during study period will be managed according to standard NACO guidelines. Cotrimaxozole DS One tablet once a day will be given to all patients with CD4 250 along with multivitamins, unless contraindicated. They will be discharged from the study once their 18th month sputum culture is negative. 