Both van Niekerk and Tryon had missed the recent home series against Pakistan also as they continue to recover from their back injuries.
In van Niekerk's absence, Sune Luus will continue to lead the side. Under Luus, South Africa had beaten Pakistan 3-0 in the ODI series and 2-1 in the T20Is.
Meanwhile, a last-minute injury to medium-pacer Masabata Klaas means she is the only absentee from the Pakistan series.
"It is really exciting to finally have this tour confirmed and announce our squad that will do duty here in India, and we are looking forward to getting out there to see our ladies prove themselves under different playing conditions," South Africa's coach Hilton Mooreng said in a media release. "India is always a wonderful place to tour and we are looking forward to the challenge that lies ahead."
As reported earlier by ESPNcricinfo, the South African contingent will be in quarantine for six days. The tour begins with the first ODI on March 7, with all eight matches scheduled to be held at Lucknow's Ekana International Stadium.
South Africa squad: Sune Luus (capt), Ayabonga Khaka, Shabnim Ismail, Laura Wolvaardt, Trisha Chetty, Sinalo Jafta, Tasmin Britz, Marizanne Kapp, Nondumiso Shangase, Lizelle Lee, Anneke Bosch, Faye Tunnicliffe, Nonkululeko Mlaba, Mignon du Preez, Nadine de Klerk, Lara Goodall, Tumi Sekhukhune