International Business Machines Corp. yesterday reported what it said are the highest fourth-quarter profits and revenues in the company's history as a result of changes in accounting methods, while Inland Steel Co. reported its first yearly deficit in 50 years and RCA Corp. said its earnings fell 6 1/2 percent in the final three months of 1982.

IBM, which is the nation's biggest computer maker and the eighth-largest industrial concern, had net income of $4.41 billion last year ($7.39 a share) compared with $3.61 billion ($6.14) in 1981. Revenue jumped to $34.36 billion from $29.07 billion.

For the final 1982 quarter, IBM said it earned $1.50 billion ($2.50) compared with $1.17 billion ($1.99) a year earlier. Revenues rose to $11.07 billion from $8.99 billion.

The change in accounting procedure, affecting foreign currency translation, boosted fourth-quarter profit by $252 million (42 cents), IBM said. It increased the year-earlier profit by $92 million (16 cents). It increased the full-year earnings by $449 million (75 cents) and added $302 million (51 cents) to 1981 net income.

RCA Corp. said earnings fell to $54 million (48 cents a share) in the fourth quarter from $57.8 million (54 cents) in the final quarter of 1981. Sales rose to a record $2.18 billion from $2.11 billion.

The company, which has interests in entertainment, electronics, vehicle leasing and financial services, said profit for the full year was up 75 percent from 1981 and that its NBC unit snapped a four-year string of declining earnings.

For all of 1982, profits rose to $222.6 million from $54 million in 1981, when the company took a one-time charge of $150 million after taxes to reflect a revaluation of certain holdings, including investments in some television programs. Sales rose to a record $8.237 billion from $8.004 billion in the previous year.

Inland Steel Co. reported a loss of $31.5 million in the fourth quarter of last year and an $118.8 million loss for all of 1982. The 1982 loss, the first for a full year since 1932, compared with 1981 earnings of $57.3 million ($2.69 a share).

The Chicago-based company said its loss in the final three months of last year compared with a loss of $1.6 million in the same period a year earlier. But the deficit narrowed from the loss of $45.1 million in the third quarter of 1982.

Fourth-quarter sales fell 23.5 percent to $624.2 million from $816.3 million in 1981. Net sales of $2.81 billion for 1982 were the lowest since 1977 and were down 25 percent from the 1981 record $3.75 billion.