John Kenneth Galbraith as a diplomat is "just another absent-minded professor," claims at least one Washington columnist in a report on Mrs. Kennedy's trip through India.

In a syndicated column yesterday, Ruth Montgomery of the Hearst papers said, "When Jackie began clamoring to visit India, the President wrote Galbraith to arrange things, but from the day of her arrival in India the 'Prof' has been pulling one gaff after another."

Among the former Economics professor's faux pas, according to Montgomery, were the following: He barely made it to the airport to welcome the First Lady but was without his official limousine. His ten-year-old son, "who shouldn't be allowed to play in a government car," had locked the keys inside. Thus, Mrs. Kennedy's sister had to ride to town in a "considerably less classy vehicle."

Later, the President mentioned in a telephone call to his wife that Caroline had not yet received any of the letters promised by her mother. The ambassador, it seems, had forgotten to mail them for Mrs. Kennedy.

Then at Jaipur, the First Lady was expected to throw a coin from her own country into a silver pot. Galbraith, said the columnist, had not informed Mrs. Kennedy of the local superstitions and was even caught without an American coin. Touring newswomen provided a quarter or two.

After Mrs. Kennedy reluctantly decided not to purchase some expensive gold statuettes at a bazaar, "Galbraith, smiling down on her, encouraged: 'Why not send the bill to the President?'" Concluded Ruth Montgomery, "Friends who know JFK as a close man with his own money wonder if Galbraith may not have gone too far with that remark."