Austin doesn't have a sister city with India. Here's our sister cities. I also added them for the other big cities. I only found one for El Paso though.
Austin
Adelaide, Australia
Koblenz, Germany
Lima, Peru
Maseru, Lesotho
Oita, Japan
Saltillo, Mexico
Taichung, Taiwan
Xishuangbanna, China
Gwangmyeong, Korea
http://www.ci.austin.tx.us/siscity/
Dallas
Brno, South Moravia, Czech Republic
Dijon, Bourgogne, France
Monterrey, Nuevo León, Mexico
Riga, Latvia
Kirkuk, Iraq
Saratov, Saratov Oblast, Russia
Taipei, Taiwan
El Paso
Ciudad Juarez, Chihuahua, Mexico
Fort Worth
Reggio Emilia, Italy
Nagaoka, Japan
Trier, Germany
Bandung, Indonesia
Budapest, Hungary
Toluca, Mexico
Mbabane, Switerzerland
Houston
Aberdeen, Scotland
Abu Dhabi, United Arab Emirates
Baku, Azerbaijan
Chiba, Japan
Guayaquil, Ecuador
Huelva, Spain
Istanbul, Turkey
Leipzig, Germany
Luanda, Angola
Nice, France
Perth, Western Australia, Australia
Shenzhen, People's Republic of China
Stavanger, Norway
Taipei, Taiwan, Republic of China
Tampico, Tamaulipas, Mexico
Tyumen, Russia
San Antonio
Santa Cruz de Tenerife, Spain
Guadalajara, Mexico
Kaohsiung, Taiwan
Kumamoto, Japan
Kwangju, South Korea
Las Palmas de Gran Canaria, Spain
Monterrey, Mexico
Chennai, India
Source was City of Fort Worth and Wikipedia.