Multiple IIF candition in ssrs report

Now I am working on a project where I have to show the dynamic value of after decimal place if user selection contain
"C"(Like 333) then report record show in round else show in one decimal place(like 333.7) and if the value of the report having the value "-1700" then report value show "open" and report value if have the value"32000" then report value show "Close"

I have tried

=iif(
InStr(Parameters!Tag1.Value, "RTD") > 0,

FormatNumber(CDbl(Fields!TagName1.Value= -7000 ),1,iif((Fields!TagName1.Value= 32000 "open","close"),

,FormatNumber(Round(Fields!TagName1.Value),0)))

but it is showing error