The government of India, concerned by a drop in the export of Indian textiles and apparel to the United States, has found a sympathetic friend in the Smithsonian Institutions, which on Thursday will open a show called "Sringar, a Pagent of Indian Costumes."

"Our object (in the exhibit) is to show that we are not trying to swamp the United States market eith cheap textiles," said Joyotinder Dixit, the embassy's minister of commerce and suppliese here. "We want to show our complete range, responding to the different tastes of the American consumer."

The collection 54 costumes ranging from ancient tribal dress to city and rural clothing from costumes for folk and classical dancers to several royal garments was organized by Air India. The airline and the Indian government split the $55,000 cost of setting up the display at the Smithsonian.

After checking with experts, the museum found the collections range of costumes and handicrafts worthy of display and circulation to other museums through the Smithsonian Instition Traveling Exhibition Service for their shorter life expectancies.

"People in the United States have a dim idea about the people of India and the richness of that culture, the diversity, the profusion of dialects," said Dennis Gould, director of SITES. "One way to show that is through this incredible assebly of costumes. It will dazzle and delight as well as inform about the richness of costumes of India.

Clothing and textiles have slipped from being India's leading export to the United States in 1975-76 to a second-place position after agricultural products, particularly sugar, in 1976-77. According to Dixit, projections are that apparel and textiles will remain No. 2 in 1977-78, this time second to diamonds and precious stones.

"We are a country of exquiste craftsmen that are being turned into machines" said Roshan Kalapesi, the researcher and designer who selected the garments for Air India. Added Kalapesi, who is chairman of the Cratts Council of Western India, "We are pushing our craftsmen to produce with no respect for quality and as a result, the craft is being lost."

Kalapesi makes a subtle statement on such mas productivity by showing in one case the real ivory bangles worn by Lambodi women side by side with plastic copies of the items now being made.

The range of design and character shows up not only in varied styles of dress but even in an exhibit of men's turbans. Thirty turbans are displayed, from a plain navy cotton style worn by the sikhs to elaborate turbans made of 73 yards of sheerest gauze worn by the Mirs of Hyderabad and royal turbans which are now part of theatrical costumes.

Costumes were chosen strictly for their design value, accoring to kalopeshi. "No attempt has been made to keep to historical periods nor to represent all the various regions or peoples of the country," she said.

Items are shown on cutout flats rather than three-dimensional mannequins to increase the mobility of the show which is expected to travel for at least two years. The flats work adequately when the garment itself has shape but occasionally take away from clothes such as asris, that normally are draped on the body.

For children caught up in the fantasies of the costumes, there will be a try-on corner where at least six garments in several sizes will be available.